Is it paint
, or is it a vinyl stick on. The vinyl only needs a heat gun to soften it and it will peel away.
can be removed with paint removers or solvents and they won't touch the Gelcoat
. But do be prepared for some discolouration where the words have been, due to being protected from sunlight. So you may need to cut and polish the area before you apply the new name. Or the old one will be seen through underneath.