Changes where one makes sacrifices, reportedly (6)
I believe the answer is:
alters
'changes' is the definition.
('alter' can be a synonym of 'change')
'where one makes sacrifices reportedly' is the wordplay.
'where one makes sacrifices' becomes 'altars' (as in an altar in a church).
'reportedly' shows a homophone (sound like).
'altars' is a homophone of 'ALTERS'.
(Other definitions for alters that I've seen before include "Changes, modifies" , "Changes to staler state" , "Changes, makes different" .)