Fence men decided partly to fix (5)
I believe the answer is:
emend
'fix' is the definition.
(I've seen this in another clue)
'fence men decided partly' is the wordplay.
'partly' indicates the answer is hidden within the clue (part of the clue is used).
'EMEND' can be found hidden inside 'fence men decided'.
'to' is the link.
(Other definitions for emend that I've seen before include "Make improvements to (text)" , "Improve by altering" , "Remove faults from" , "Make correction in written material" , "change" .)