set a wet sponge (or sponge with wax remover) on top for 20 minutes or so first. Hopefully this will soften the crusted stuff before you start. I've got paint flaking in my louvers where they were not prepped correctly before repaint.

Scott B. "I'm a self-made man... I started with nothing, and I still have most of it!" 68 360 rusty B'cuda 'vert (GO Fish)13.59@ 98.72 mph 69 340 GTS stock 14.18@ 95.60 mph 01 5.9L Ram 1500 Quad Cab 4x4 01 3.5L 300M 16.23@ 86.97 mph