I installed both Dynon servos after I had been flying for a year or two. They are relatively easy to install. The biggest challenge is doing the pitch bracket because it is recommend that you rivet it through the bottom skin. (My plane wasn't painted when I installed them.) Some people have just riveted (or bolted) the bracket through the rib that the bell crank is attached to.
I HIGHLY recommend you buy the wiring harness from Stein for both servos. Although it will have extra wires, if you ever upgrade to a SkyView, the servos will already be pre-wired. Also, I put DB9 connectors on each servo, so facilitate installation and future maintenance.
To secure the wire run in the fuselage, I used zip-tie pads with the sticky pad removed and glued in place with Goop Automotive Trim Adhesive.
The roll servo goes in the right wing and I installed conduit with a pull string, when I built the plane, so those wires were easy to run. One of the two brackets that holds the right aileron bell crank is replaced and the roll servo bolts to that.
While you can operate the Auto Pilot from the D100, I recommend installing the AP74 control head. It just makes it easier to use the Auto Pilot.
Good luck!