Going in with damaged green tin (8)
I believe the answer is:
entering
'going in' is the definition.
('enter' can be a synonym of 'go in')
'damaged green tin' is the wordplay.
'damaged' indicates anagramming the letters.
'green'+'tin'='greentin'
'greentin' is an anagram of 'ENTERING'.
'with' is the link.
(Other definitions for entering that I've seen before include "Going inside" , "Going/coming in" , "Coming in" , "Starting" .)