Well,
I was 100% wheelchair bound for more than a year, and no way to change myself...
In a wheelchair I'd say impossible....
In bed, can be done, but will depend on your dexterity...
Myself, I'm just getting able to change myself in bed again, after some spinal surgeries and complications...
Not walking yet, but can do like 10 feet with walker and help...
Just ask to help out, you will figure outa way to do it...