The Clutch Tools Kit includes a big ass bolt (BAB) and a special spanner wrench.  All Mohawk Aero clutches and shaft couplers are made with a threaded end to make removal from the engine's taper shaft a snap.  This makes it far easier to take it off than any other clutch hub!  Common gear pullers bend the centrifugal Tango and RK400 clutch hubs, and will destroy the internal parts of the GT4/5 units.   To use the BAB, simply insert a drift rod (available upon request or use your own 3/8" bolt or steel rod) of proper length to bottom out in the PTO taper shaft's 1/2"-20 thread pocket, so that it stops the BAB before that bottoms out on the hub's retaining shoulder.  Hand-thread the BAB against your drift, attach a big ass monkey wrench to it, and smack it a couple of times, tightening it, with a small sledge hammer, until the hub pops off of the PTO shaft.   No need to lock down  the engine crankshaft from turning either, making life much easier.  
 
The spanner is used to hold the GT4/5 hub in place while torqueing the 1/2"-20 engine PTO shaft retaining bolt to the required 45-90 Ft Lbs., and is required for installation.  
 
Sold seperately:  
BAB   $29.99
Spanner Wrench $19.99 
Drift w/nylon collar:   $4.95