Is there any software to do this? I didn't find any useful information on the internet so I am asking here.
You cannot get the exact code, but you can get a decompiled version of it.
The most popular (and best) tool is Reflector, but there are also other .Net decompilers (such as Dis#). You can also decompile the IL using ILDASM, which comes bundled with the .Net Framework SDK Tools.