One tip would be to soak the nylon, so that it will stretch and be more pliable. When it dries it will shrink and be on drum tight.
It will go through, but sometimes you really need to finesse it.
Good news, once it's on you don't have to remove it to disassemble.
I have the Urban ERT on my PS90, I think it's a bit more versatile in terms of carry positions. Plus, if you purchase the right adapters, you only need one sling shared amongst several platforms.