Once you try and tighten the bolts, if it is still leaking then no, you don't have to pull the motor to change the gasket. You will however need to remove the motor mounts and jack the engine up some to clear everything. You may also have to remove the oil pickup tube inside the pan once you get it loose, depending on how high you jack the engine up. I did it on my 00 GT and it wan't too difficult, just time consuming.