u dont have to make a new image... you can just backup your kext files
i backed up System.kext(didnt need it but oh well safe than sorry), and seatbelt.kext(+the .orig file) I also should have backed up my video card driver, and my sound kext.
then edit the com.apple.boot.plist in the Extra folder, find where it says, Mach_kernel(I use voodoo so this is what its like for me) then change that line to mach_kernel.voodoo(if your using that kernel.)
then just Run the updater!, i recomend booting with -v -f -x and the first boot after installing it, then just replace your kexts. I only replaced the seatbelt.kext and it was okay, then I just redownloaded and installed my video driver kext and my audio, which is all successfully working!
good luck btw, reboot and pray
EDIT:
it would also be helpful if you would put your computers specs and what version of OS X your using, and all your computer info so we can give better details for your hardware

, if you dont understand what I mean, look below at my sig and see what details I included