Clean all the pieces and pre-paint the top and bottom screen end pieces..
Have some wood boards on the floor and some other smaller Hard-Wood blocks (and a rubber dead-Blow Hammer is handy). Start by having the Top and Bottom pieces ready, as well as the 2 long bolts.. 4 Hands are probably handy..! Start one corner of a screen Top and Bottom into the end pieces AND start the nearest long bolt..just enough to keep the corner from coming out (top and bottom). Slowly work you way across, guiding each bend into place..a little at both top and bottom and taking up what slack you need on the Long Bolt, as you go.. End up with the Long Bolts pretty snug.. You must work every convolution into place, so expect some paint will need re-touched.. Once together, you can install the screen assemblies in the Nose Piece.