Changes to new alerts (6)
I believe the answer is:
alters
'changes' is the definition.
(I know this)
'new alerts' is the wordplay.
'new' indicates an anagram.
'alerts' with letters rearranged gives 'ALTERS'.
'to' is the link.
(Other definitions for alters that I've seen before include "Changes, makes different" , "Changes, modifies" , "Changes to staler state" .)