Doing what DrOzz is recommending will delete the kernel module for your other kernel, though -- they won't both work anymore, only your new kernel.
The way to get both of them working at the same time is to run the installer with the --extract-only option. This will create a directory named the same as the installer (without the .run at the end). cd into that directory, and then cd ./usr/src/nv and run make nvidia.o && make install -- this won't delete the old kernel package, but will just create a new one (you HAVE to be running the new kernel), and install it.
You can then delete the directory that the installer created when you gave it --extract-only.