Libraries for the at tiny micro controllers

I need to modify some libraries to work with the at tiny 84. I was wondering if there was a way to modify libraries in general to work with the at tiny, by adding code to the .cpp files,

I specifically need to do this for the virtual wire library. I found the patch file for the virtual wire library (in the .patch format)but I am unable to apply it. The .patch file seems to have some out of place #, +, and - symbols when opened in notepad. Help in this regard would also be appreciated. Thanks in advance.

Those are part of the patch file format. You use the "patch" command in anything other than Windows to apply it.

How do you apply it on the library through Mac OS?

In a terminal window, change to the folder with the original file in it, then use “patch < /wherever/the/patch/file/is”