Exhaust flap removal-Newbie question

[kamp0087]

Ok, stupid question, but how am I supposed to get the remnants of the old flap off? Grind off the nub and then drill it out? Are these little nubs threaded into the exhaust pipe? They don't look like rivets. Bought the boat like this, it's missing both flaps.  I'd like to get new flaps that come with 2 screws but not sure how these come off.

1973 CV-19 455 Olds Jet
Thanks for the help

[Plugcheck]

Never seen them like that, every one that I have worked on had two screws holding that small reenforcement strap on.  My guess is those are pressed in place, so I would try to wedge them out.  If that fails, a Dremel cut off to remove the heads, then pull out with grips/slide hammer.   For the future, and just my opinion, but I'd drill and tap for a SS 8-32 screw.  The flappers are important.

[kamp0087]

Thanks for the quick response. Wanted to make sure I wasn't missing something obvious or an easy way to remove.  Guess I'll drill it out.

[fireman24mn]

Looks like the engine is out can you see a hole on the back side where you can insert a punch?

[cv-19]

 If I remember correctly they are pins with knurled ends and are pressed in. You should be able to pry under the metal piece and get them out. Tap the holes and use stainless screws, they should come with the new flappers.You can use stainless sheet metal
screws if the hole is too big to tap .

[cv-19]

 I think the rivits are close to the edge ,I would be careful if you drill not to enlarge the holes too much.

[kamp0087]

Thanks guys, with your encouragement I used a hammer and flat screwdriver to get underneath and pry them out. They were pressed in but came out fairly easily.  Just didn’t want to ruin the exhaust if they were supposed to come out some other way. There’s nothing to see from the motor side.  I’ll get a kit with screws.
Thanks

[Cali special]

They always come right off immediately. Just leave it