Put gloves, a screw gun and a claw bar into a bucket. This will make carrying your tools easier as well as provide a receptacle for unfastened screws.
Place a ladder against an exterior wall or just under the eaves. Grab the bucket of tools and climb the ladder.
Set the bucket of tools onto the roof while standing near the top of the ladder. Put on the gloves and retrieve the screw gun from the bucket.
Unfasten the screws holding the panel closest to the edge of the roof and place the screws in the bucket.
Remove the claw bar from the bucket, and slide it between the roof panel and roof. Pry upward to free the panel from the roof. Once loose, carefully drop it to the ground.
Move on to the next roof panel, unfastening the screws and prying it up with the claw bar. Repeat the process until all the roof panels have been taken off the roof.
Carefully walk over the roof once the panels have been removed to find screws that might have been missed. Unfasten the remaining screws and toss them into the bucket.