Take the plunge outside of Sunset Strip (6)
I believe the answer is:
divest
'strip' is the definition.
('divest' can be a synonym of 'strip')
'take the plunge outside of sunset' is the wordplay.
'take the plunge' becomes 'dive'.
'outside of' suggests removing the centre.
'sunset' with its middle taken out is 'st'.
'dive'+'st'='DIVEST'
(Other definitions for divest that I've seen before include "Relieve (oneself of garment)" , "disrobe" , "Undress" , "Strip off clothes, take away" , "Strip (someone of clothing)" .)