Put the back row in a different order (9)
I believe the answer is:
rearrange
'different order' is the definition.
'rearrange' can be an answer for 'order' (I've seen this before). I am unsure of the 'different' bit.
'put the back row' is the wordplay.
'put the back' becomes 'rear' (I can't explain this - if you can you should believe this answer much more).
'row' becomes 'range' (range can mean a row or chain of things).
'rear'+'range'='REARRANGE'
'in a' acts as a link.
Can you help me to learn more?
(Other definitions for rearrange that I've seen before include "Again work out" , "Order differently" , "Tidy up" , "Put new structure" , "Give another order" .)