WordNet sense 1 (reduce to a fine, unmixed, or pure state; separate from extraneous matter or cleanse from impurities):

refine

WordNet sense 2 (bring, lead, or force to abandon a wrong or evil course of life, conduct, and adopt a right one):

reclaim, reform, regenerate, reform, regenerate

WordNet sense 3 (set straight or right):

amend, remedy, repair, remediate, repair

WordNet sense 4 (make right or correct):

correct, right