I have placed the seal when a 10 qt pan required removal. Parking brake bracket needs to be removed. If it has already been modified to be removable, you are one step ahead.
As long as you don't have a rope type seal that is pinned in place, the seal above the crank can be spun out using a small punch against one of the seal's ends. ZF stays in place. No fun, yet it was successful. Be sure to offset the end of the new seals about 3/8" from the plane of the oil pan block surface.