what i would do:
1) call your "stealership" and ask if there are individual parts available for the broken mirror;
2) if there are available parts, ask for a copy of an exploded view of the mirror assembly(they can send it to you by fax if u have one or go there and they'll gladly make a copy for u... if none, then chances are, it's only available as a whole assembly.
replacement mirrors- i would look at eBay :-)
DIY... i will reserve my comments on that. DIY really depends on one's wrenching savvy... for some it's easy as a cold beer going down on a hot day; for other's it ain't so... ;-)
In this case... you may or may not have to pry the inner panels open to get to the hold-down screws that hold the mirror to the door. OR, if u'r lucky, it just might be having to pry a small triangular plastic cover directly behind the base of the mirror.
Good Luck.
__________________ ay sino caddi ububblaem?   Heaven won't take me; and Hell just knows I'll take over...! | 
