Don't you need a new display and not transducer? If so, cut the cable off at the fitting on the other end and get a fitting for the new display to put on it.
If you need to replace the whole shebang, then that transducer isn't going to come out without a haulout and replacement. If the depression next to it is solid glass, and the head
of the new transducer fits inside it right down to the bottom of the depression, you could clean out and fill the depression 1/2 way with silicon - be sure to get all the air bubbles out of it - and carefully sit the new transducer in the filled depression and let it set up. This will work fine, and definitely last until you decide to haul out
and replace - it will probably last for good. Epoxy
will work similarly, only be permanent.
There is nothing "inside" the old transducer except some solid state components potted in epoxy
. You cannot cut off the old transducer and mount a new one on top of the stump.