Grass skirts either sex modelled differently (8)
I believe the answer is:
reformed
'modelled differently' is the definition.
'grass skirts either' is the wordplay.
'grass' becomes 'rye' (I've seen this before).
'skirts' means to remove the middle letters (retain the edges).
'either' becomes 'formed' (I am not sure about this - if you are sure you should believe this answer much more).
'rye' with its centre taken out is 're'.
're'+'formed'='REFORMED'
'sex' is the link.
This may not be right. It may be part of another bit of the clue.
(Other definitions for reformed that I've seen before include "Restored - mended one's ways" , "Changed for the better" , "sort of church" .)