1st make sure its not a leak at the tube/ case area, then if its coming out unhook the battery, Remember to put a mark on the flex plate and converter.
Check the transmission to block bolts, if they are loose really check over the case holes. If it has been run loose
and that sucker can move a bit up/down/side to side, it can ruin the new seal pretty fast. The case holes will be out of shape.
Drain the pan and remove the the dip stick tube.
Plus the normal , drive shaft , linkage , lines , speedo, cross member,
Floor jack, piece of 2x6, watch your fingers

if your over 60 take all your tools and beer cooler down on the floor with you. After it's out check the converter hub also.