appliying patch

Hi
I have a set of source files for the dwim utility, in the directory /usr/local/src/dwim-1.0.
I have a patch for adding an enhancement to dwim. The top line of the patch reads
diff -rc dwim-1.0-vanilla/Makefile dwim-1.0-raspberry-ripple/Makefile

Which commands should I use for applying the patch to the source tree?

You would have to show us more of the "patch" to be sure but it looks like you will have to manually edit the relevant files to apply the patch(s)