Convert an ASP.NET application on production in II6, back to Solution

I have to modify an ASP.NET Web Forms application which is currently on production on a Windows Server 2003 in II6.

The problem is that I didn't develop the application and there is not anymore the Visual Studio solution used to develop the application. Moreover the application lies under a website where other applications are running and the connection strings are stored in the global 开发者_运维问答web config file.

I want to modify the application without compromising the version that is actually online.

How can I bring the production version back into a solution file? Many thanks