The roof trim needs to be put on before the metal roof rail, to put the wood trim on all you need is a ladder and a nail gun. The trim is placed on the top part in two different steps. First, the trim underneath needs to go on before the top part so that the top section has a place to go in. The bottom part of it can have small chunks of two by fours, and that’s what the top trim is nailed into. Be sure to nail the parts with the thick wood, so it doesn’t miss. The metal railing that goes around the trim needs to be placed on after the trim.
The window trim should already be pre measured according to the shed size so they just need to be placed around the window and nailed in, and then repainted. The trim is put on after the window is already in.
The door trim goes around the door after the door is placed on but not all the way bulleted in, once the trim is placed on the hinge side of the door you bolt the door in and finish the rest of the trim.
The vents can be put in at the end and basically can just be measured out and cut either on the top or like in the picture of the shed above the vent can be cut on the front of the shed.