Here’s a tip for putting uprights together that made them a piece of cake!
Start by putting 3 nuts on the allen wrench to guide down into upright.
Then I used a stubby phillips screwdriver to hold the nuts down. The phillips fits right into the hole of the set of nuts.
You can then very easily start each screw, then dump the extra nuts out, and tighten the screws up.
Made this step so easy after I struggled and cussed a little for about 5mins…lol