Agency to change names (5)
I believe the answer is:
means
'agency' is the definition.
(I've seen this before)
'change names' is the wordplay.
'change' indicates an anagram.
'names' anagrammed gives 'MEANS'.
'to' acts as a link.
(Other definitions for means that I've seen before include "considerable income" , "Resources; intends" , "Ways" , "way" , "Intends - capital" .)