Best way to not bang your rad when taking off the pipe is to take off the top anti-vibe bracket with the pipe. Generally the twisting of the pipe binds it up and then when pulling it off... bam! Ding in the rad.
The finning tool is a good idea but doesn't work on the little rows of fins on most motorcycles. Time, patience, and a nice set of wide bladed tweezers are the ticket. Don't forget to add some water wetter to the rad fluid when rehydrating the beast.
Be cool.... hehe
Sly