Revised a muddled deed containing it (6)
I believe the answer is:
edited
'revised' is the definition.
(I've seen this in another clue)
'a muddled deed containing it' is the wordplay.
'a muddled' indicates an anagram.
'containing' means one lot of letters goes inside another.
'deed' anagrammed gives 'eded'.
'eded' placed around 'it' is 'EDITED'.
(Other definitions for edited that I've seen before include "Prepared copy for publication" , "Changed for going out" , "Prepared a paper" , "Entrust, commit, deliver" , "Changed text" .)