Mirror in front of the front door?

That depends on the architecture of the house.

Typically its not that hard, one side, usually the inside of the door panel, you'lll find screws. Simply unscrew it, take the molding off, take out the glass & replace it with the glass you want...

It depends on how much is being replaced. You might get away with just unscrewing the hinges off of the old door and screwing on a new one, or more likely, removing the trim from around the door,...

That your front door should be somewhere else.

be carfull its old and brittle. Remove the window crank handle with a handle clip removal tool or reach behind the handle with a small pick and remove the clip.Remove the door pull screw access...