He can remove trendy shackle (7)
I believe the answer is:
enchain
'shackle' is the definition.
(I've seen this before)
'he can remove trendy' is the wordplay.
'remove' is an anagram indicator (move the letters again).
'trendy' becomes 'in'.
'he'+'can'='hecan'
'hecan' is an anagram of 'encha'.
'encha'+'in'='ENCHAIN'
(Other definitions for enchain that I've seen before include "Make fast" , "Put in fetters" , "Secure" , "Bind" , "Hold fast" .)