Where the chrome ones off ebay you purchased metal?
As for changing the handles, I have not done it before. I don't think it's going to be difficult. I am sure you have to take off the inside door panel in order to get to the handle mechanism. Maybe others will say what they did to change theirs
easy swap just pop off you door handle 2x 10 mm nuts i belive and slighty pull the handle out the front too release the handle from the locking clip on the little bar inside the door good luck about a 20 min ordeal..