Great question!
So first, I would like to address the need for soaking in acetone. As far as I know, the only reason one would have to soak in acetone is to un-stick the glue that holds the magnets in place. This is a short diversion is for those who do not know the history.
The magnet issue from a very long time ago came about because at one time, the magnets between different runs of minis and grands weren't always put in the same way. So if someone ordered a
mod from one run and then bought another from the next run, there was the potential for magnetic disagreement between the two doors, making swapping doors between the two mods nearly impossible. That problem was fixed a long time ago. When these mods are assembled the magnets go in the same way every time so that this doesn't happen again. Extra or single doors are now shipped with the magnets loose in case the person ordering the door has one of the older mods.
Okay...onto your real question. Rob or I can certainly test it. It is not recommended (as you already know) to soak the entire
mod in acetone as there are plastic parts...and plastic never plays nicely with acetone.
Instructions for putting magnets in the doors are simple. Lay the
mod flat on the table, door side up. Remove the door.
Place the new magnets on the magnets that are on the mod.
Take a sharpie and mark a dot on the exposed side of the magnets.
Then, place a dot of super glue in each magnet hole on the door. Put the new magnets in the glue, ensuring that the dotted side is the side going in the glue. This way, you will never put your magnets in backwards.