Chisel out Flange and replace or...??

Hi, new to posting but have been browsing for a year or so. Have a 1977 tri level ranch, needs LOT's of updating, so am replacing/repairing here and there as I can afford and have time.
Current issue is toilet in basement. Needed new wax ring due to leak, so pulled toilet off. Plan on replacing with Fluidmaster bowl gasket (used upstairs already, what a breeze). Anyway, I have 3 in ABS pipe with the metal flange surrounding the ABS, set in the cement floor, not bolted in anyway. I am attaching a pic so you can see what I mean as I'm not sure my description will be clear.
So, am not sure if I should try to remove the metal flange part by chiseling out and using a replacement of some sort (clamshell or whatever someone suggests) or try to leave in place and alter?? You can see in the pic that a chunk on the right is missing altogether.

Of concern is it does not "appear" to be level, I will probably use tile for new floor, however, may use linoleum so need to be sure the height issue isn't an "issue".

Can someone advise me what they would do, or, in my case, what would be the simplest/easiest for me? I would prefer to do it right the first time, and since I am currently working just a few days a month, have all the time I need. No helpers or other income, so need to do myself.

Thanks all for advice, I think it's a great thing you're all doing helping people with your expert advice and experience. Good Karma.

You can pick up repair rings at any hardware store.
We secure using a 1/4" rotohammer and lead anchors.

Terry, thanks so much for the rapid response- one more goofy question- do I remove the old flange? I assume I do, but want to be sure.
Again, thx a billion....

The repair flange will go over the existing flange.
I prefer to leave the old one in place.
Anything to keep the old flange secured.

Terry -
maybe a dumb question but -

how does that repair flange seal to the old flange?

how does that repair flange seal to the old flange?

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Why would you?
The repair flange is farther out, the wax doesn't even touch there.

Maybe the picture is confusing me - looks like the repair flange has its own plastic funnel which would glue over the old flange -

or is it just a ring?

The repair flange is the red ring only.

Thanks - makes sense now.

flange

I would remove the metal one and install a two piece "clamshell" one. That way there is no possibility of a leak between the new flange and the old one. And, I have seen toilets which would not seat properly because of the "bumpouts" for the fastening screws.

I would remove the metal one and install a two piece "clamshell" one. That way there is no possibility of a leak between the new flange and the old one. And, I have seen toilets which would not seat properly because of the "bumpouts" for the fastening screw

Click to expand...

We install about five of the red rings each week.

There is no seal between the swiveling metal ring and the plastic closet flange.
The swivel ring is only meant to be used to secure the flange to the floor.
A flange embedded in concrete isn't going anywhere.
The new red ring is just for holding new closet bolts.
You could also drill the concrete and use threaded anchors.
I prefer the ring.