Whats the easiest way to bend aluminum trim into a simple 90 degree angle. ???? (THIS) piece will be hidden so it CAN be a little ugly.
Take a section of plywood, and clamp it down stationary. Figure out the two lengths of the aluminum sides, to locate where the bend will be. Mark this out on the plywood. You will have a drawn out "L" shape pattern.
Using your skill saw, on the clamped down plywood, do two straight cuts into it, to form the marked out "L" shape. You are creating a "form template".
Once the cuts are made, and you check the measured cuts, etc - Get a helper to hold the plywood in place (vertically), while you run the length of the aluminum thru the plywood "template".
The aluminum will form to the 90 degree angle cut-out, and you should have what you need.
This method is good for installing aluminum in non-visible areas, such as substrate flashing.
Good Luck on the project.