I am building a Loyal, too, and have installed a Raboesch bow thruster. It's their second smallest size. Pictures attached show a bit of the process. I cut the initial holes with a hand held drill, then opened them to fit the BT tubes with a Dremel grinding tool. I made a small block to support the BT while the 2 part epoxy putty set, and left it in place. Excess length of about 1/8" was left on the tubes to be filed off once the putty cured. I filled the gaps around the outside the with the same putty and sanded it smooth.
The BT is positioned right under the smallest, forward hatch, so the 3 screws holding the motor to the base can be removed with a long Phillips screwdriver.
I had trouble with the flat impeller on the BT coming loose early in its life. I replaced the impeller with one made of brass stock, epoxied to the motor shaft. A Proboat ESC completes the installation. Oh, yeah, the boat has a single 6 volt SLA battery. It kicks the bow around very nicely, at zero forward speed, good for docking and such.