Well, after reading the whole string concerning this subject and facing
multiple road trips spanning about a week, I decided to attempt to replace
the sorry excuse for speakers behind the original grills in the front door
panels of my 'new' '86 weekender interior in my '83.5 wasserboxer gl
(whew!).

Quick conclusion: it was suprisingly EASY!

Per the string, yes, the front grill is attached to a rear 'retaining nut'
behind the panel. But the real trick was, you DON'T have to take it off!
Obviously, first take off the door panel and disconnect the speaker, but
leave the speaker grill on. I put the removed liner on a big rug so as not
to tear it up. The original Blaupunkt speaker was glued to the grill and
visible from behind the panel. Take a pretty skinny flat-head screw driver
and insert it in the space inside the rear of the speaker grill between the
speaker and the side of the grill 'tube'. Gently twist the screwdriver to
break the glue joint between the speaker and grill. I just kept doing this
around the speaker until the weak spots 'popped', but be careful, it looked
like the speaker grill 'tube' may break with a little too much force. After
the glue joint has been broke, the speaker will just fall out by turning
the panel over. I took the speaker to Circuit City and found that a Kenwood
3 1/2" 2-way speaker ($40 /pair not on sale) was a good match. There are
two 'wings' on either side of the speaker which I assume are used to attach
the speaker onto a door panel. I took needle nose pliers and bent the
'wings' back until it would fit snugly into the original vw speaker grill
'tube'. There is  a metal lip that extends past the speaker on the Kenwood.
I placed a bead of 'goop' glue around this lip and pushed the speaker into
the speaker grill 'tube' and allowed to dry overnight. Note, I didn't
scrape any of the old glue out of the speaker gill 'tube', maybe I should
have, Oh well. Anyway, I did the whole deal to the other side and
reinstalled everything back in the morning.

Excluding the time to buy the new speakers and glue drying time, I'd say
the whole thing took about an hour. The new speakers sound great! And the
original vw grills look a whole lot better than the Kenwood grills too!
Well, I guess the rear speakers are next. Good luck!

tony
'83.5 wasserboxer gl weekender