Take turns to change a ten, counterfeit (9)
I believe the answer is:
alternate
'take turns' is the definition.
('alternate' can be a synonym of 'take turns')
'change a ten counterfeit' is the wordplay.
'change' becomes 'alter' ('alter' can be a synonym of 'change').
'counterfeit' is an anagram indicator.
'a'+'ten'='aten'
'aten' is an anagram of 'nate'.
'alter'+'nate'='ALTERNATE'
'to' is the link.
(Other definitions for alternate that I've seen before include "Go in turns" , "Happening or following in turns, one after the other" , "Take turns" , "Occur in turn repeatedly" , "Occurring in turn repeatedly" .)