You don't actually need an incidence tool, although they're nice to have.

Prop the tail up so that the wing LE and TE are the same distance from the floor.
Now measure the distance from the Stab/elevator's LE to the floor and the TE to the floor.
Now check to see if the prop is at a right angle to the floor. (It's not actually easy to do that with the prop. It's much easier to use a flat piece of plywood or thin board bolted in place of the prop. Just drill a hole in a yardstick and use it instead.)
Take a look at the plane from the side and see what it's nose-to-tail centerline looks like to you. If it's not parallel to the floor......

What is the kit? ARF?