Cutting the exterior panel

[Yakherder]

I have a RotoZip with the same type of attachment that I use to cut metal. You have more control on this type and have control of the depth of cut. A jigsaw has a reciprocal blade and the depth of cut could be critical as you don't want to be hitting the inside wall, wiring or frame. You would need the shortest blade possible or even have to cut one down.

I'd think just cutting a square about 3/8" deep or even a bit less depending on the thickness of the outside wall. All you want to do is gain access to what is behind the outside wall. Everything else can be removed by hand or cut out with a razor after that. You may also have to attach something inside to affix your shower to.

[dkwheeler]

Get an RV center to do it, that way your wife will not remind you of the screw up every time it leaks.

[travelin texans]

Originally Posted by dkwheeler

Get an RV center to do it, that way your wife will not remind you of the screw up every time it leaks.

I'd have to chance listening to the wife!
The odds of the service center doing any better job is about nill, the difference is the $150 an hour labor.