Synonyms for Customize:

n.

change, reverse, modify, turn into, revise, convert, vary, alter, transform, make into. customize (noun)
tailor-make, customise, custom-make.

v.

modify to personal expectations (verb)
tailor-make, custom-make.

Other synonyms:

Other relevant words:
modify, convert, revise, reverse, alter, vary, change, transform.