I have a 1991 ford econoline van with a 302 it has mail bearing seals that need replacing how hard is that to do.

 

Never had to do it on a 302 but I would think for the front seal you just pry it out of the timing cover and tap the new one in.
For the rear one you need to drop the trans, remove the flexplate/flywheel, pry out the old seal, fit the new one and reassemble.
Hopefully better info from those who have done it will follow.

 

No big deal pull trans then fly wheel and seal is right there pull that and put all together sounds quicker then it is if you have a friend that can spin a wrench it will cut down time wise to about 3 or 4 hrs