How to manage people who used to be your peers ?

The situation should be looked in a positive way. Since you worked as peers before so most probably you know them much better and can utilize their strengths and work around their weaknesses. They should also be treated as your other subordinates with respect, dignity, and understanding.

Sometimes a promotion can suddenly change your relationship with co-workers from “peer” to “boss.” It’s not an uncommon scenario, particularly in companies with strong succession plans. However when this happens it often creates an awkward and uncomfortable set of dynamics, and there’s no blueprint for how to manage them.

Your focus must shift to building a strong team from within them. It is not about keeping or making friends. It is about creating results to further the goals of your company. Your peers will not accept you as their boss until “you” accept that you are their boss.

RESPECT & HUMILITY  are two great quality that Leaders must have and display and I think treating your peers who managed you in the past with respect and humility is the starting point. 

Change as a result of a promotion is a very delicate process to undergo in terms of inter-personal dynamics at workplace, both for the newly appointed manager and for his old-peers/new subordinates. 

1. Change needs time to actually take place. Take your time, be patient & down-to-earth.
2. Have someone else announce the promotion (mostly done as such)
3. Don't assume your position too soon with too drastic changes. "Remain one of the guys" and give them time to adjust. They'll appreciate this.
4. Be friend to all or friend of none. In your new position you don’t want to start a new level in your career/company by conveying "favouritism". If you must, then let it be based on performance, which off course needs time to be (re-)evaluated.
5. Be wary of envy; it is the most malicious emotion in workplace, naturally ignited by evidently proving "better than others" who may want to prove your disqualification through undermining your authority. Don’t underestimate it and don't stimulate it by following the steps aforementioned.

This really good question, Thank you Mr. Bader

You need to establish your credibility and authority, without acting like the promotion’s gone to your head. How you walk this line will depend on your organization and your leadership style, but here are some general rules to make any transition smoother.

 Signal the transition

 In most companies, it’s someone else’s responsibility to announce your promotion.

Tread lightly at first

 You probably have tons of ideas about how to lead the team. But don’t introduce any major overhauls right away. You need to demonstrate your new authority without stepping on toes or damaging relationships.

Establish your authority

 Demonstrating you’re in charge doesn’t mean making a show of your newfound authority. Instead take actions that establish your credibility and indicate how you’ll work as a boss. One of the best ways is to meet with your team, as a group and individually, to talk about your vision.

Distance yourself

You can no longer have close, personal friendships with your former peers. “You can’t continue to have relationships in the way you did before. This is a loss for everybody but it’s part of the deal. You don’t need to become aloof and unavailable, but you may want to attend fewer social gatherings

Try out new personas

 Because you need to determine new ways of interacting with your former peers, you’ll likely need to try a few things out. you’re not drastically changing your personality, or your leadership style, but you’re prototyping to see what works for you.

Deal with the disappointed competitor

 If one of your peers was in competition for the job, you have an added layer of complexity to address.. In some cases, you might just need to let the person adjust to the new situation. But it’s important to make it clear that you value him as an employee and that you plan to advocate for his development.

Make use of the advantages

 Of course, there are some upsides to being the boss of former peers, “you’re more likely to find someone you trust to give you feedback, and pull you aside and tell you when you’ve screwed up.” Leverage those existing relationships to ask for honest input.

Look beyond your team

 During this type of transition, it’s easy to become overly focused on your former peers. But don’t forget to deal with your new peers and your new boss

If one believes in human values then there is nothing different required for working with anyone.

Being peers one would have known their potential so ignite that and use it productively.

Good answers given by Tahir Amin, and Divyesh Patel. I echo with them. I had this situation couple of times in my career. In the beginning it looks awkward to give directions to your direct reports who were your peers before, but, once you take initiatives to build the team by having regular conversations regarding company's strategic goals and expectations of you from your direct reports slowly things become normal. So, it's just a matter of time until you build mutual trust as boss and subordinate.. Also, you wouldn't be spending time to micromanage them as you know their strengths and weaknesses very well. 

Only I do my best with all the activity and diligence and give them what they want to find out information or to answer their questions, so overcome each one and also be gained friendships and greatly appreciated

Intelligent and good measure

The five fingers on your palm are of unequal lengths, The longest is the Middle Finger. If it was made boss and during a fist fight it decided to stand out and put the others down to work, do you know what it would look like?

So when its time, even the boss has to come down and work! As long as your peers see you doing that they will never have a problem with your position!

Simply by :

1_fullowing all working operative orders ,plans , policies & regulations

2_commitment & specification  

3_ never have a  discussian about personals & famlies problemes

4_professional, occupational & certain

5_ training & developing in your career are must