When I got my colostomy bag in May, a worker had to come into my hospital room and show me how to change it. It was painful as I was still tender there, but my main issue was looking at my stoma without throwing up. I'm horrible at these things and up till now, my wife has changed my bags.
Knowing I need to do this myself, I changed it myself (I knew what to do as I've helped my wife change mine every time). It wasn't as bad as I planned, but did take longer as she's got a better view of my stoma than I do (using a stencil to cut the board opening to fit my stoma).
She was relieved I did it myself. I'm just ashamed it took me this long to work up the guts to do it myself. I'll be doing it now on myself till I have my reversal in February.