My trick is to setup, then push through the hips to get the butt high off the bench. This pushes the traps harder against the bench and makes it much easier to unrack. Once you bring the bar out into position, you can lower the hips again.
The other advantage of this is that it reminds you of how tight the upper back should be and to get the glutes fully engaged, which you should be doing if setting up a proper arch.
You'll get used to it. When I started training solo, I found it hard to unrack with 100kg. Now I'm very comfortable well above my max, to the point where lift-outs throw me off.