Climb down where CD needs to be remixed (7)
I believe the answer is:
descend
'climb down' is the definition.
(I've seen this before)
'cd needs to be remixed' is the wordplay.
'to be remixed' indicates anagramming the letters (I've seen this in other clues).
'cd'+'needs'='cdneeds'
'cdneeds' anagrammed gives 'DESCEND'.
'where' acts as a link.
(Other definitions for descend that I've seen before include "Move downwards" , "Plunge" , "Come down" , "Move downward" , "Climb down" .)