He gives the old a new lease of life (9)
I believe the answer is:
renovator
'he' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'the old a new lease of life' is the wordplay.
I cannot quite understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is present in the answer.
'a' is within the answer.
'new' could be 'n' (common abbreviation eg NT for New Testament) and 'n' is located in the answer.
'of' could be 'o' and 'o' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'gives' is the link.
Can you help me to learn more?
(Other definitions for renovator that I've seen before include "Restorer of good condition" , "One freshening up" , "One who restores" .)