Writing to revise the laws about credit (6)
I believe the answer is:
scrawl
'writing' is the definition.
(scrawl is a kind of writing)
'revise the laws about credit' is the wordplay.
'revise' is an anagram indicator.
'about' indicates putting letters inside.
'credit' becomes 'cr'.
'laws' is an anagram of 'sawl'.
'sawl' placed around 'cr' is 'SCRAWL'.
'to' acts as a link.
(Other definitions for scrawl that I've seen before include "Write in slovenly manner" , "Crawls away from bad writing" , "Roughly put down" , "Illegible handwriting" , "write hurriedly" .)