Change point for old gate (8)
I believe the answer is:
turnpike
'old gate' is the definition.
'turnpike' can be an answer for 'gate' (turnpike is a kind of gate). I am not certain of the 'old' bit.
'change point' is the wordplay.
'change' becomes 'turn' (turn is a kind of change).
'point' becomes 'pike' (pike is a kind of point).
'turn'+'pike'='TURNPIKE'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for turnpike that I've seen before include "Toll gate/road" , "Pay money to get past this" , "way in the US" , "Toll gate" , "A paying way" .)