How to convert desktop website into mobile website?

no there is no easy way to do that .. the process of converting a website to a mobile website, depend on the site itself, does it have so much graphics or not, how you will position your data and so on .. so my advice to you is to build a new website design but make it optimized for mobiles from the first beginning .. for coding you can use bootstrap or foundation4 to help you with the responsive functionality of the css.

1. Create a Mobile Version of Your Current Site. The quickest way to make your site mobile-friendly is to create a mobile version of your desktop site using a conversion platform like bMobilized or Duda Mobile. ...
2. Use Mobile Plugins on Popular CMS Platforms. ...
3. Use a Mobile-first Responsive Design.

you have two wayes:

 

1. CSS "Recomended"

Using Css's commands to create media queries with spreated devices' screens. ex. @media screen and (max-width:1024px) { your code}

and you can use this site to testing your code: www.responsinator.com

 

2. Other Paied Services over the inernet

You can create a separate mobile version of your website, like:

• MobiSiteGalore
• Mofuse
• BMobilized
• ConvertWebsite
• Mobify

best and easy way by Css .

If you're using MVC architecture, you can do that by changing the views to ratios views. Or using the jQuery mobile interface for that., using themeroller, which enables you to make your own theme. for extra information contact me.