I will state that putting the long screws that hold the can together was a PITA. Never done this before so I was clueless as to a method. It had me more frustrated than a one armed wallpaper hanger. Why aren't these screws stainless or aluminum. It was at least 45 minutes to get these started.
You're likely well practiced now.... but I'd like to offer a tip to all those who don't know it already...
When doing up bolts (and indeed most things "threaded") it can be very easy to get them either cross-threaded, or (particularly if it's in a soft material) just cut a new thread (which can only happen so many times before there's nothing left!)
Over time, I've learned that the best way to make sure a bolt "starts" properly is to apply a gentle pressure and turn it BACKWARDS. You will feel it "drop" as it goes past the end of the existing thread. Now turn forwards and you should have a perfect thread engagement, first time, every time.
As for getting long bolts to line up, I've never found a sure-fire way to do it. If they're not captive, the best I can offer is to hold the device going back together such that the bolt or rod you're inserting is as near as possible to vertical, and lower it in. Once you get close to where the thread SHOULD engage, slowly "wind" it in circles around where you hope the thread is, in increasing and decreasing circles until you "find" the post or surface. Use your fingers as eyes and visualise the surface. (Looking at it first so you know where ribs, lumps and bumps are in relation to the hole you want). Once you've found the hole, the backwards rotation (above) can help confirm you've got the right one.
One final tip.... never do the first bolt up tight. Do it up just enough to keep it in position. You may have to wiggle things to get subsequent bolts in. Once all are in place, do them up gently only, make sure all mating faces have, and only then do things up firmly. (Otherwise, it can be easy to do things up with a bend or twist - which can make bearings and bushes be out of alignment - making things stiff and increasing wear)