How difficult removing the front seal with the crank in the way would be, i dont have any idea. However the Miller tool for installing the seal assumes the pump and crank are installed in/on the block. It has a tapered sleeve that fits over the snout and allows the seal to be pressed into the pump housing with the larger sleeve and bolt. Im sure there are ways to install the seals without the special tools, but i would recommend them as they make the install about as fool-proof as possible. The front seal miller tool is part # 6780.