Try one’s manipulative procedure in the theatre (5)
I believe the answer is:
taxis
'manipulative procedure in the theatre' is the definition.
(theatrical procedure to manipulate bones)
'try one's' is the wordplay.
'try' becomes 'tax' (I've seen this in another clue).
'one's' becomes 'I's' (Roman numeral).
'tax'+'is'='TAXIS'
(Other definitions for taxis that I've seen before include "Cars with a driver for hire" , "Cabs" , "return to right place" .)