this is how i do mine, that seems to help, it's kind of hard to explain though. I get some cheap towels from wal-mart, wash them a whole bunch so they have no lint and then cut them into small squares, and use them instead of papertowels, much cheaper the towels cost 1.50 each, and it takes me usually 3 squares per change, ok, then i have all my stuff ready, i lay my wafer, two towel pieces and a bag on the floor, i stand up, put the tail of the bag i am taking off into the brown trash bag thing that comes with them. I peel it down slowly, cleaning around it, while the bag is still partway on. Ok, right before i pull it all the way off, i push on my stomach right above the stoma, which i learned accidentally will make stuff come out if it is near there. i just do that until nothing comes out anymore. I also have two paper towel squares laying on the cabinet. I remove the whole thing, cover my stoma wtih the paper towel square, kind of wrappign it. i lay down, keepign the stoma covered. Lay the wafter, a paper towel squrae and the bag on my leg. then i very quickly, pull the old towel off put the wafer on and cover with a another towel. Ok, then i press around the wafer quickly making sure i get it down evenly and then snap on the bag. So far, it's worked great.
You can practice doing that with an empty toilet paper roll and some kleenex and pieces of card board.
I hope that helps you some.
Also, i keep four of the boxes that my bags come in, with a wafer, precut, a bag, a trash bag, four towel squares and paste in them, that way if i have a need fro an emergecny change, it's all ready, and before i take anything off, i get the new wafer ready.
It takes me about 8 minutes to do the entire thing, including getting the box out, pasting the wafer, laying stuff out, then cleanign up afterwards.