it isn't so hard at all..first thing you can try is this, for a stock kernel:
- get a rpm-packaged version of the 2.6.7 kernel from somewhere, for your distribution. then just install it, I guess..
and the second way, which I prefer:
1) get sources from kernel.org
2) decompress them to /usr/src/linux-2.6.7/
3) cd into the directory
4) read the README file in that directory for instructions, which I guess are these (I'm running 2.6.6, so they shouldn't differ):
(now check that you have everything you need, change if you want)
make all && make modules_install
5) after the kernel is compiled, assuming you got no errors, copy System.map from where you are, and arch/i386/boot/bzImage (or perhaps zImage?) to /boot but DO NOT OVERRIDE THE OLDER FILES THERE. instead, rename the old files to another name, then copy those I said above
6) edit your bootloader's config so it recognizes the new kernel. also, edit the old kernel section so that it points to the renamed files - now you have two kernels
7) reboot to the new kernel. if you get a failure, reboot and select the old kernel - this is why you didn't override the files. now you can do this again, and check that the kernel config is correct...
these are the instructions, mainly...README-file in the directory, after you decompress the sources, tells you everything you need. this isn't so complicated, not nearly as it might sound
after the first time you'll want to do it again, and again, and again...