Fix article with nothing to protect it (4)
I believe the answer is:
Here is my best explanation:
'fix article' is the definition.
'nail' can be an answer for 'fix' (I've seen this before). I'm not certain of the 'article' bit.
'nothing to protect it' is the wordplay.
'nothing' becomes 'nil' (eg nil is zero in football).
'to protect' is an insertion indicator.
'it' becomes 'a' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'nil' going around 'a' is 'NAIL'.
'with' acts as a link.