You can find some solvents, purpose designed to dissolve bedding compounds & sealants, if you do some digging (or know someone with a Chemistry degree).
Though, the simple method is to take a sharp; Filet Knife, Utility Knife (with a thin handle), or an Exacto Blade. And slip the knife's cutting edge in between the hardware
to be removed & the boat. So that you're cutting the sealant's bond, prior to pulling the part. Also, sometimes a putty knife with a good edge on it works well too.
But when you do things this way, removal's a lot easier & less destructive, than just trying to remove things via brute force.
I'm a big fan of the Filet Knife for thses jobs, as due to it's flexibility (& sharpness), you can use it to get into a lot of places which are impossible to reach with other cutting tools.
Also, for some hardware
configurations, you can use a piece of thin wire or cordage (monofilament/braided fishing
line, thin Spectra, or Dental Floss, etc.), with handles on both ends of it, to cut through the sealant as well. Often employing a sawing motion with it, in order to cut through the bond. Although on some bits, you get lucky, & a straight, garrotte type motion will do the trick.
These techniques, in their various forms, work on most any type of sealant or bedding compound. Including stupid stuff, like 5200. Although with the latter, it does take a bit more work.
And given the oddly shaped, & unique bond lines on some bedded parts
, you'll sometimes have to use your knife to make a series of "plunge cuts", all of the way around the perimeter of the item to be removed. Sometimes going completely around it several times, in this manner.
Other times you'll get lucky, & one clean slicing path with the Filet Knife will do the job. And the part will practically fall out.
Then, once the parts
are off, removing the silicone residue is pretty straignt forward: Scrapers/Putty knives, a wire brush & or wire wheel
in the chuck of a drill, plus various other abrasive means. 3M Scotchbrite pads, sand paper, etc.
That, & of course some of the old standby solvents. Some of which I'll use in conjunction with a 3M Scotchbrite pad, for stubborn bits.