Now the chaps are coming in to change (5)
I believe the answer is:
amend
'change' is the definition.
(amending is a kind of changing)
'now the chaps are coming in' is the wordplay.
'now' becomes 'ad' (I've seen this in other clues).
'the chaps' becomes 'men' (I've seen this before).
'are coming in' indicates putting letters inside.
'ad' placed around 'men' is 'AMEND'.
'to' acts as a link.
(Other definitions for amend that I've seen before include "Make minor improvements to (a document)" , "Revise" , "Modify - edit" , "Make corrections to (eg, document)" , "Make small improvements to" .)