F-Body Europe

does anyone know of a web site that show how to section the rear rubber bumper cover?
I bought some 29.5 x 9 x 15s because in the class I want to the biggest tire you can run. but the rear where the bumper curves in very slightly at the back looks like it could give me some trouble..... *evil grin whips out the sawzall* ill take care of it but I dont want to just chop the bumper cover and not have a rolled edge.. I would like to keep it so the wheel well looks stock.