First five characters remove third lock, replacing it with nothing at all at this address (5)
I believe the answer is:
abode
'this address' is the definition.
(abode is a kind of address)
'first five characters remove third lock replacing it with nothing at all' is the wordplay.
I cannot quite understand how this works, but
'first' could be 'a' (first letter of the alphabet) and 'a' is found in the answer.
'remove' could be 'de' (I've seen this in other clues) and 'de' is located in the answer.
'nothing' could be 'o' (looks like zero - 0) and 'o' is located in the answer.
A single letter 'b' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'at' is the link.
Can you help me to learn more?
(Other definitions for abode that I've seen before include "stay" , "Pad" , "Home or domicile" , "House, home" , "Dwelling, residence" .)