The best way to release something that's stuck, say a spigot? (6)
I believe the answer is:
faucet
'a spigot?' is the definition.
(both can mean a tap in American English)
'the best way to release something that's stuck say' is the wordplay.
'the best way to release something that's stuck' becomes 'force it' (forcing something stuck might release it).
'say' shows a homophone (sound like).
'forceit' sounds like 'FAUCET'.
(Other definitions for faucet that I've seen before include "Spigot, tap" , "An American water tap" , "Tap (US)" , "North American tap" , "Pipe" .)