Can someone tell me how difficult it is to install a side view mirror on the drivers side?

I've had the mirror replaced on an Explorer and it was pretty straight forward. Do you have the entire unit to replace or just the glass itself?

Just changed both sides on a 99 Villager (same exact as Quest) took about 1/2 hour per side. Very easy. New mirrors are available from aftermarket body parts suppliers, Keystone, Neco, certi-fit, etc.