Pull a bird going to church (6)
I believe the answer is:
wrench
'pull' is the definition.
(I know that pull can be written as wrench)
'a bird going to church' is the wordplay.
'a bird' becomes 'wren' (wren is a kind of bird).
'going to' says to put letters next to each other.
'church' becomes 'ch' (common abbreviation).
'wren'+'ch'='WRENCH'
(Other definitions for wrench that I've seen before include "use force" , "Jerky pulling movement" , "Twisting tool" , "Painful parting" , "Kind of spanner or severe twist" .)