This process uses the flywheel attaching bolts and fender washers and shims (or more washers) to pull the seal into the engine block at an even pressure so as not to mess up the seal. You will need 3 of the flywheel attaching bolts and three 3/8 inch inside hole diameter fender washers and at least three of the 1/2 inch inside hole diameter fender washers (these need to be thicker and larger than the 3/8 inch ones). You will need about 9 to 12 more of the 1/2 inch fender washers or some shims later on to move the seal back into the engine block. The bolt goes through the smaller fender washer, then the larger fender washer then into the crankshaft flange.
MAKE SURE YOU DO NOT PINCH THE SEAL BETWEEN THE FLANGE AND WASHER! Go easy and go slow and you should not have any problems. It does not take a lot of pressure to move the seal in and you can move the washers as needed to make sure the seal goes in evenly!
Here is the process: first coat the edge and side of the rear crankshaft flange with grease and then push the new seal up to the engine block finger tight just so it sits there. Place the bolt and washers at the 2,6 and 10 o'clock positions and tighten the bolts finger tight and snug to hold the seal steady. I coated the outside edge of the seal with RTV and then you start tightening the bolts 1/4 turn at a time in rotation until you have the seal in about a third of the way. Then back the bolts out until you can slide two more washers under the large washer and then tighten again and repeat until the seal is all the way in.
I attached pictures of the one I did so I hope this helps.