"to turn over a new leaf"
to completely change your behavior or attitude in order to be better than you were
to reform and begin again
ameliorate, amend, better, clean, convert, correct, cure, improve, mend, rearrange, rebuild, reconstruct, redeem, regenerate, rehabilitate, remake, remodel, renew, reorganize, repair, resolve, restore, revise, revolutionize, rework
Literally, turning over a new leaf
(of a calendar). - - - - ->