In the pictures, you can tell where the old seal was compromised because you can see dirt between the metal and sealant and also rust near fastener holes.
The steps are:
1. Tape around portlight to prevent scraping and also sealant creep.
2. Remove portlight frame with putty knife without bending the frame.
3. Clean off all old silicone from boat and frame. First with chisel, then with dremmel (like a dental tool).
4. Acetone all surfaces for final clean.
5. Tape frame to help cleanup.
6. Apply sealant liberally.
7. Screw in fasteners part-way, until sealant oozes out. Leave for 24 hrs.
8. After sealant cures, screw in all the way for gasket effect.
9. Take tape off.
10. Razor blade off any excess sealant.


