Assuming this is a manual, standard mirror, I have the same problem on the same exact car and I took the mirror apart today to see how.
Open the driver's side door and pull the plastic covering away from the mirror adjustment handle. The cover is triangular and covers the whole area in front of the window. It will probably give you some trouble coming off, but it just snaps off. Beneath that are several nuts. Remove these and your mirror will come off, bringing its cover with it.
Now for the problem I've run into: where to get a new one? I've tried two auto parts stores and cannot find a replacement. Both claimed they couldn't even order it from Plymouth. If my on;line search (which brought me here) fails, I'll be trying a junkyard. I'd be willing to bet the one from a '97 Dodge Neon would fit perfectly. if I can't find a Plymouth. Good luck with yours.
Found one for about $34
carmirror.com
take off the one screw in the plastic behind the mirror adjuster and there is three nuts that hold the mirror on take them off
how do you replace the camshaft position sensor on a 1997 plymouth voyager 3l
on a 1997 blazer, how to remove drivers side mirror under your handle to close the door is two 7mm bolt and behind your handle to open the door is a Philips screw and that plate behind it comes off then CAREFULLY remove the door panel trust me you don't want to break the plastic then you will see your mirror bolts and electrical wiring
twist it out and twist in the new one or you can just replace the mirror
belt assembly for a 95 Plymouth voyager
You replace the rear wheel bearings for a 1997 plymouth breeze by taking it to a very skilled mechanic and just waiting it out. If you want to do it yourself I can't help you with that.
you must remove the fuel tank to replace the pump.
You have 2 choices, you can pay an astronomical cost (around 600 for the drivers side mirror alone w/o installation) or you can buy replacement glass and glue it in yourself.
see answer for the 1999 Breeze
Take off the door panel and unbolt the mirror housing
You must remove the timing belt to get to water pump.
Go to the following website. It will show how to remove the door panel and the side mirror. kwmuth.com