In a PM recently this is some info I sent regarding the install:
In short, there are several methods to making it happen. The method I use involves removing the upper boss/mount on the new mirrors to make them into a basic 3 post design. I used a sawzall to remove the stud in the aluminum casting and a grinder with a flap disc to flatten the mount so it doesn't protrude. I then remove the studs in the mounts and use bolts (m6-1.0x15 and 25mm lenths) along with fender washers mounted from inside the door skin to distribute load. The sail fin trim covers the hardware nicely. Tweeters in this location may need attention as there is a possibility for clearance issues (depth).
I then hold up the new mirror and line up the mounts on the new base to the doors; the upper and lower mounts will line up to the current holes in the doors. The holes need to be opened up to allow clearance for the base of the casting at the mounts to recess into the door. I will guess and say the holes need to be about 1". I use a step drill from Harbor Freight (don't judge...I use nice tools but these are genuinely hard to beat!) to make that happen and it goes quick. Prep the uncoated metal once done to keep them from rusting. I believe the lower center mount lines up with the current middle hole on the older door as well; same principle for opening the hole applies.
I used aftermarket mirrors and had to use the plug on the old mirrors for the power functions to work properly. Once you are ready with the holes, apply the foam gasket to back of the mirror bases and hold them up to the door. Take the m6-1.0 bolts and fender washers and install them from the inside of the door panel with a generous amount of red loctite to make sure they do not back out.
I have used this method on two vans now and have a ton of offroad time on them and have experienced zero issues to this point. I actually expected them to fly off in short order, but they have struck Joshua Trees at speed on the Mojave Road and survived. I would highly recommend a set of bolt on C-Betr convex blind spot mirrors as they make up for the lack of visibility.
CBetr Blind Spot Mirrors – US Made since 2001
I will shoot some better photos tomorrow, but this sums it up. I'd say each door could be completed in about 30 minutes max even with the plug swap, but I am pretty familiar with it so that time may change for a first timer.