Unprotestantize, a rather uncommon and specific term, refers to the act of removing Protestant influence or characteristics from something. While there may not be widely recognized synonyms for this particular word, we can explore alternative phrases or expressions that convey a similar meaning. To undo the Protestant influence, phrases like "eliminating Protestant elements", "removing Protestant traits" or "eradicating Protestantism" might be considered. Though none perfectly encapsulate the nuanced meaning of unprotestantize, these alternative expressions can still convey the general idea of diminishing Protestant influence from a particular context or subject.