[villagetinker]

Almost any handyman can install these, especially if the replacement is the same brand as the original. I have done a few, and have run into some problems when switching brands, the units are slightly different sizes, the vent is in a slightly different location and the holes for the mounting screws in the cabinet or the strip on the wall are in different locations. NOTE: if you have a finished backsplash that was installed after the microwave I would strongly suggest staying with the same brand.
In any case, if you have an EXTERNAL vent all of the ones, I installed required changes to be made to swap from INTERNAL circulation to EXTERNAL vent.