WordNet sense 1 (insert words into texts, often falsifying it thereby):

falsify, interpolate

WordNet sense 2 (cause to change; make different; cause a transformation):

change, modify

WordNet sense 3 (make or become different in some particular way, without permanently losing one's or its former characteristics or essence):

vary

WordNet sense 4 (remove the ovaries of):

castrate, neuter, spay