Bend the first diode into an "S" shape, with the lead from the silver banded end bent 90 degrees 1/2" from the body.
The lead from the other (black) end bent 90 degrees 3/8" from the body.
Trim 3/8" off each lead and insert the silver banded end into the power transformer terminal 4. Do No Solder.
Insert the black end into the upper hole of C4 and solder. Trim any excess.

The red and black heat shrink does not come in your kit. I added that for extra protection from shorts.