How do i alter my xcover II to use radio without plugs?

While looking for an antenna, that has an 3.5mm plug built onto it, i found out an discussion of converting android 2 phone to FM radio.

So i am asking of this: has somebody made a tutorial, on how to hack the existing 4.1.3 jellybean to open radio without earpuds/phones attached to stereo jack?

Currently i am using cutt off jack from old phones, as a redneck hack, it kinda works, but id like to keep it watertight while on a beach/poolside.
So how do i hack my phone, so i dont need earpuds to play radio signal from my edited by ddp own town radio mast, less than 1 kilometer away, with better than exellent signal?

ty in advance for responces.