For me, I found the easiest way to get the polycarbonate (Lexan) panels into the black ABS supports is to stand the assembled panels on end, then work them into the supports slot using a rubber faced mallet and tap lightly the bracket. Don't worry about slightly bending the panels, there made of Polycarbonate. This is what bullet proof glass is made from. Tuff stuff against hail. Once in, use the 4 furnished small screws to hold the panels in place to the brackets. The screws are small so try and use a magnetic tipped Phillips screwdriver to line up the screw with the holes. If you're old like me, you'll never find them.
I suggest wearing a pair of thin gloves when aligning the panels in the bracket slot. You're more than likely going to pinch your fingers, *&#@. I did, lol. Word of caution. the 4 expanding bolts that are used to hang the brackets are 10mm (.394") in diameter. Use a 10mm drill bit. If you use a 3/8" drill bit like I did, I had to enlarge the hole slightly. Be careful not to make it too large. The bolts won't expand enough to hold the brackets to the wall.
Two people make the assembly and hanging much easier. Going to order another 40" x 40".
Bubba 
John 
