Removes blunders by head of security (6)
I believe the answer is:
strips
'removes' is the definition.
(stripping is a kind of removing)
'blunders by head of security' is the wordplay.
'blunders' becomes 'trips' (trip is a kind of blunder).
'by' means one lot of letters go next to another.
'head of security' becomes 's' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'trips' put after 's' is 'STRIPS'.
Can you help me to learn more?
(Other definitions for strips that I've seen before include "Undresses" , "layers" , "Takes off clothes" , "Gets undressed" , "Long narrow pieces" .)