We are getting ready to change out our exhaust tips for new Stainless Marine angle tips (Thanks Fred). I removed the plastic surround plate and saw what looks like either urethane or a real thick silicone around the existing tips. I have not tried to pull the old tips out yet. Before I do I figured I'd ask for some opinions.
Anyone have any suggestions so I don't have to repair the transom when I'm done.

I removed the ones on my Formula. Inscrew the screws holding the exhaust tip to the transom. Use a razor blade to cut into the adhesive all the way around the tip between the tip and the transom. Then use a 4' piece of 2x4 and trim the end so it will fit into the exhaust tip. Now move the 2x4 up and down, then side to side to loosen the tip from the transom and slowly remove. Worked great on my 14 year old boat.

My tips have always came out with no work. Not sure what type of sealant was used on both my Fountains, but on both the amount was scarce and not permanent. When I reinstalled the tips, I filled the gap with 5200. No leaks.

Yea,what he said. had to give mine a few raps with
a hammer and 2x4,but thy came out. Gettin the new ones
in with the new revolution marine manifolds and merc
silent choice is another story........But they went.

Mix dishwashing liquid with water in a spray bottle. Do not remove hoses from the exhaust manifolds inside the boat. Spray soap solution thru transom holes and into exhaust hoses from the outside of the boat, then just slide the new tips in the transom holes and they should slide fairly easily into the hose. Just make sure that the hose clamps are loose inside on the exhaust hose. Mine went in very easy even with thru-bolts for the muffler tips.

Mine were glued in with a 3m 5200. Tough stuff! I ended up heating mine up with a propane torch hot enough then they come loose. Very stinky and smoky job, Do it outside. The fumes are choking, On the first couple I rigged up a hydraulic puller and this helped yank them out but I found just apply more heat and they just about ploped out themselves.

I installed my muffler tips with clear silicone.

what Raypanic said on mine with 5200. Lotsa gel and glass would've come with 'em without HEAT. Careful though....heat will discolor the gel around the tip flange. Just a little brown color, but my transom mount Corsa muffs covered it as the cans are a little larger in dia. than the flanges of the original tips.

Well, we started last weekend but could only go so far because Bill had to modify the center ones to fit.
So, here are the before and during. Hope to have a finished one soon.