Question: My main duct running from my HVAC unit runs right up to the bottom of my stairs. I want to shorten it so people don't have to duck when walking down the stairs to my finished basement.

Ok, I took the end piece off, no problem. Yet, looks like I'll have to do some bends to get it back on once I shorten the rectangular piece. Is there a special tool to do bend the end piece so I can put the cap back on?