Change around odd bits of loin, sent back for butcher (8)
I believe the answer is:
mutilate
'butcher' is the definition.
(I've seen this before)
'change around odd bits of loin sent back' is the wordplay.
'change' becomes 'mutate' (mutating is a kind of changing**).
'around' indicates putting letters inside.
'odd bits of' means one should take alternating letters.
'sent back' is a reversal indicator.
The alternating letters of 'loin' are 'li'.
'li' in reverse letter order is 'il'.
'mutate' enclosing 'il' is 'MUTILATE'.
'for' is the link.
(Other definitions for mutilate that I've seen before include "Severely maim" , "Disarm perhaps" , "Injure severely" , "Damage beyond recognition" , "Cut off a part of the odd mule at it" .)