On my 1978 the door mirrors are a little eye sore....Swamp water from Florida will do that...

Yes, you can replace it yourself.  I've done it from a thread I found somewhere.

Took my mirrors off when we painted. It's actually not that hard -   I removed the door glass (2 bolts) in order to get access to the mounting studs inside the door. Your glass afjustments should not change since the mounting bolts for the window are fixed in position...

So even thought it looks like part of the sport mirror comes off somehow without removing the whole mirror it does not come apart unless you remove the whole mirror assembly and it must be done by the 2 bolts inside the door panel. I will look but if I understand  you remove the 2 glass stop bolts or 2 bolts removes the glass from the door?  will research some more but did not seem like yo could get to the bolts unless you do as you have stated glass stop bolts or glass bolts. Thanks BB78

That's correct Mark. The 2 pieces to the mirror are screwed together form inside the base, so the mirror does need to come off in order to separate the sections.

Again . . . soaking the mirror in G-A-S-O-L-I-N-E (not a lot, just enough to cover the glass when face down in a shallow pan) once you have removed the assemblies from the car and taken them apart, will loosen the glass in a few minutes.  Been there, done that. 

Thanks for the info might as well do them while the door  inside is off and get rid of the scratched mirrors. Thanks again hope it's easier then the door hinge bolts???