I changed the libgomp source code of gcc. How can I install libgomp alone

Question

I recently did some change about the libgomp of the gcc-4.7.0 source code. How can I install libgomp alone. I know I can intall the total gcc that have been changed. But maybe I will do some change about the libgomp again, and I don't want spent much time install the changed gcc again. I want to how I can install the libgomp source code alone. Thank you!