Iv done it without the tool with no problems just copy the pattern and go in the middle don't re stake the same spots of course I'd check the bell housing bushing as well for excessive wear also torque converter hub these things can cause the seal to fail if you do have wear replace the bellhousing and torque converter as well as the flex plate and crank spacer to be sure flex plate and spacer should be replaced any way with the updated parts check out hd flex plate and sonnax billet spacer the bushing is non serviceable and a good used housing with a new seal already staked in cab be purchased for under $100 shipped I believe check out cobratransmission.com also check to make sure the spacers on the oil pan pads were housing bolts thread into are there you can check the offset with with a straight edge and a feeler gauge google the procedure it'll have pictures and the color code info for the spacers.