Find a sunny spot to place the sundial. Set the sundial in the site and mark around its base with baking flour. (Flour will not harm the sundial's finish, and it washes away easily.)
Remove any grass or other plants at the site and level the ground. If the sundial is not level, its readings will be off.
Place the sundial back on the site. Check again to make sure it is level by placing the level on the top surface of the sundial. Check it twice; the second time, turn the level perpendicular to the direction you used for the first measurement. Modify the site as necessary until the sundial is level.
Use the compass to find due north. Rotate the sundial until the highest end of its style, the part that casts the shadow, is also pointing directly north.