Installation using the provided illustrated installation manual can take as little as 6 hours and up to 14 hours depending on the number of surfaces on which the parts are installed, and how many total parts are in the kit for a specific aircraft model.
It will take your mechanic approximately 3 hours to install the templates on the aircraft and double check the measurements. The remainder of the time is gluing each Micro Vortex Generator in the cut-out of the template, and cleaning up any excess adhesive that may squeeze out under the base of the Micro VG when pressed in place. Some aircraft models also contain strakes which are installed with provided hardware.
Here is a video of an installation