@raquettelaker2 you will remove the 4 screws on the black surround. then pull the entire unit out. their will be a wiring harness that you can un plug. Next their is a metal rectangle CAGE that holds the unit into the mounting black plate. on the sides their is a locking tab on the left and right sides, you will use a flat head to lift them and then the unit will slide out the front side.
Now ANY single din radio will work. The question you have to ask is do you want a water proof outer door like i have in my boat and most boats or d you want to buy a waterproof unit itself. a standard car single din will work just fine with a water proof face door. Next is do you want to be able to add amps later, add a wired remote for the transom? If so i would go with a Kenwood Head Unit. The Kenwood KMRD765BT
https://www.amazon.com/kenwood-KMRD765BT-Marine-Receiver-Bluetooth/dp/B019FEW4XC/ref=sr_1_1?ie=UTF8&qid=1493407488&sr=8-1&keywords=kenwood+kmrd765bt+marine+cd+receiver+with+bluetooth is a marine receiver with RCA outs that are 4v for plenty of power to the 3 RCA outs for amps in the future, Blue tooth and all of the modern features one could want. it is $129 and that is a good price for what all you are getting. It will accept a transom remote also.
As for the black dash component you can reuse the one you have or replace with a cover this is up to you as this is a water proof unit.
If this did not answer you Q ask more and i will check back as you have the same dash as mine. Also take a look at my thread near the beginning at my radio info and see if any of that will answer questions.
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Not Penny's Boat
1993 190 Horizon 5.0L EFI http://www.smwebhead.com/phpBB3/viewtopic.php?f=3&t=111361977 14' CMF Skiff SOLD
2015 Emotion Stealth Angler 11