The Weapon-R bottle is attached to the wire mesh on the backside of the rad. You remove the bracket from the back of the bottle and then use a pair of oversize washers to hold it in place on the mesh.
Here's the sequence that I used:
Remove the bearclaw.
With a 32 oz plastic cup nearby, remove the hose from the rad neck and drain the fluid into the cup. Dispose of properly so no critters can get into it (they are drawn to antifreeze like flies to cowpatties).
Remove the stock reservoir and remove the overflow hose.
Remove the rad shrouds and then the mesh.
Test position the bottle until it doesn't interfere with the clutch cable. Fix to the mesh.
Attach the hose that comes with the Weapon-R bottle to the lower end of the bottle before you re-attach the mesh to the rad.
Holding the mesh and bottle to the correct position on the rad, position, cut and attach the upper end of the hose to the rad filler neck.
While holding the bottle higher than the filler neck, add coolant to the bottle until the new hose it full and approximately 1/4 of the bottle is filled.
Lower the mesh and bottle into position and attach to the rad.
Reinstall the rad shrouds.
Give it a test run and watch for fluid movement in the hose.