Rolling the Fenders

How exactly do I roll the fenders on my 89 coupe? I'm Putting 98 cobras on all the way around and im doin 275's out back and 245's up front so I think I'm gonna need to roll them, I dont wanna hurt the paint or body real bad.... so any suggestions? Thanks for your help guys...
 
I have heard that some people have used a baseball bat between the tire and inner fender. Stick it in and rotate the tire and the bat rolls down the innner fender lip.

One of the major tire chains had a tool you could rent that did the job. The tool cost $700 if you wanted to buy it, and there was a long waiting list to get it.