Change relating to the whole (8)
I believe the answer is:
integral
'the whole' is the definition.
(I've seen this before)
'change relating' is the wordplay.
'change' indicates an anagram.
'relating' is an anagram of 'INTEGRAL'.
'to' is the link.
(Other definitions for integral that I've seen before include "Belonging as an essential part" , "contributing to unity" , "Maths function; entire" , "A component and indispensable part of, like triangle" , "using no fractions" .)