Regret shoehorning outdated record into lease (6)
I believe the answer is:
repent
'regret' is the definition.
(I know that regret can be written as repent)
'record into lease' is the wordplay.
'record' becomes 'EP' (abbreviation for extended play record).
'into' is an insertion indicator.
'lease' becomes 'rent' (synonyms).
'ep' placed within 'rent' is 'REPENT'.
'shoehorning outdated' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
(Other definitions for repent that I've seen before include "Show remorse" , "Be contrite, ye sinners" , "Deplore" , "lying on the ground" , "Feel guilty" .)