Sounds like a really thick skin that may have been soaked a little too long.
I have a technique that might help you if the problem you are having is getting
that second lug in the rim loops, which always seems to be the hardest.
Get some wire and loop that around the rim loop. You can then put the lug into this loop of wire
you just made. Then you can tighten the lug and pull the rim down to get the remaining lugs into
place. Finally you can cut the wire and put the last lug in.
I have pictures in this thread.
viewtopic.php?f=14&t=3227&hilit=new+techniqueI hope you have some good pliers, because pulling that thick skin with the lugs in place is going
to be tough.