The removal
The old vents have a potmettal base, we need to save that.Remove all the screws by taking the nuts off the bottom.Tap the screws from the bottom up so you can pull them out.There full of dried up putty so this may take a bit. cleaned mine up and reused them during assembly.With a hammer and one inch carpenters chisel ,start at the two front opening corners and slowly tap under the pot metal until it starts to lift. The same with the back. STOP HERE.Look inside the vent, you should now see a small crack in the back and sides of the pot metal. If you do take the chisel and give it a good tap on the side where the seal is not yet broken. The whole thing should now separate. You will now have the pot metal flange broke in half with the bottom part still stuck in the hull and the top part screwed on to the bottom of the vent. Remove those screws now and place them aside.Remove and throw out the broken flanges in the hull. Clean out the old sealer.Take the top section of the flange and cherish it , its not replaceable don’t break it don’t loose it. Slowly file off the rough edges until the are flush with the base of the flange, spray and prime and store away.You may now Finnish the vents as you see fit. If you have the money ,get them refinished. Fur many of us like me I just used some bondow to fill the pot marks primed it and then spray painted them black.Time for a trip to Home Depot This will be next.Thanks Uwe