There are Windows version of Unix/Linux commands, including patch, here:
On either Windows or Linux the command you need to enter should be:
patch -p1 -i jamp_game-2.patch
(On Windows, either copy patch to your codemp dir, or include the path to patch in the command line)
To run make under Linux:
The patch should create a file called "Makefile" in the game directory. If you have added new files to your project, you will have to edit Makefile to include them in the list of OFILES (e.g. g_mynewfile.o)
Otherwise, change to the game directory and enter the command "make". A .so should appear.