For the front seal you need to pin the flywheel and also the camshafts should be held using the tool, then you need remove the lower timing case cover and you can knock the old seal out. when I did my seal it was fairly difficult getting it to go into the case cover.
I used a socket of the same size and hammered it in lightly with a mallet.
For the rear main seal, you'll have to mark and drop the driveshaft and exhaust. then unbolt the tranny, take off the drive plate or flywheel (depending on trans type) and then replace the rear seal. (also not sure but I think the pilot bearing may have to come out as well. this is much more time consuming and difficult under jack stands.
I would just take it to an independent shop, saves you the hassle unless you're really keen to do it. Good luck
