There are a few things I do, to try to reduce the discomfort, though the reduction is minimal.
First, with a new binder, if it's absolutely just too tight, I will take it and stretch it over the back of a chair and leave it there for a day or two. That helps, as long as the chair isn't so wide that it ends up tearing the binder.
Another thing I do, especially in the hot summer, when those damn things just drip in sweat within a few minutes, is I put on an A-shirt ( a small tight one) underneath the binder. This makes it easier to get off, and I just pull on the A-shirt underneath from behind and over my head and it takes the binder off with it. I usually take off my binder that way too, even if I am not wearing an A-shirt underneath. Just grab a hold of the bottom of the binder from the back and pull it over my head.....if that makes any sense?
Good luck with it; once I had a binder so tight, I struggled and fought with it to get it on. Once on, it was so tight, it was provoking an asthma attack, which I don't get very often. I struggled and struggled to get it off, but couldn't and eventually passed out with it still on me. When I came to, I still couldn't get the damn thing off me, so I ended up having to cut my brand new binder

off of me. I bought a size larger next time around.