change undergo a change; become different in essence; losing one's or its original nature; "She changed completely as she grew older"; "The weather changed last night"
modify,
alter,
change make less severe or harsh or extreme; "please modify this letter to make it more polite"; "he modified his views on same-gender marriage"
lighten -
alleviate or remove (pressure or stress) or make less oppressive; "relieve the pressure and the stress"; "lighten the burden of caring for her elderly parents"