Employs tricks to remove leader (4)
I believe the answer is:
uses
'employs' is the definition.
('use' can be a synonym of 'employ')
'tricks to remove leader' is the wordplay.
'tricks' becomes 'ruses' (a ruse is a trick or ploy).
'to remove leader' means to remove the first letter.
'ruses' with its initial letter taken off is 'USES'.
(Other definitions for uses that I've seen before include "Employments" , "Consumes; treats" , "deployments" , "Functions, applications" , "manipulates" .)