I know this threads a little old, but I might still do some good

I read most of this, but admit I skimmed a bit, so if I somewhere missed a sentence that says the same thing as me, I'm sorry

I find I have really quite large hips, and when I first got my binder (the correct size for measurments) I could not get it on, tried for a few days every which way and nothing seemed to work. Then I hit on gold, and use this method every day. First, I turned in inside out, then stepped into it, arm strap end facing down. Slowly and carefully I worked it up until the edge was right at the widest part of my hips. By that point in time, the binder was touching a lot of skin, and would pretty much refuse to move any higher anyway.
What I then did was reach down and grab the arm straps, and pull them up my body. Having the material over your hips makes the rest of it slide easily over and up, meaning I just had to work it a little, and it was right up to the top of my chest. It was a little difficult getting my arms in the holes, but you get used to the angle pretty quickly

Then all I had to do was pull the doubled up bit out from underneath, and fit it down over my hips.
To take it off I just work it over my shoulders and take it off like a T-shirt, but I suppose you could step out of it too. Hope I helped