Father and mother backed park getting overhaul (6)
I believe the answer is:
revamp
'overhaul' is the definition.
(I've seen this before)
'father and mother backed park' is the wordplay.
'father' becomes 'rev' (I've seen this in other clues).
'and' means one lot of letters go next to another.
'mother' becomes 'ma' (Ma is another word for mother or mum).
'backed' is a reversal indicator.
'park' becomes 'P' (abbreviation as on an automatic car's gear lever).
'ma' backwards is 'am'.
'rev'+'am'+'p'='REVAMP'
'getting' acts as a link.
(Other definitions for revamp that I've seen before include "Give new appearance to" , "Patch up or renovate" , "Give makeover to" , "Refurbish" , "face-lift" .)