Esson,
With the grip removed, next remove the handbrake knob itself. This is done by inserting a small screw driver, (or equivalent), into the two holes in each side of the handbrake handle shaft - just below the knob itself. The idea is to push the locating pins in, (both sides), to release the knob which sits on a spring. Once the knob is removed the metal ring simply slides over the handbrake shaft. The main plastic base is again fastened to the car by plastic locating pins. To release, simply pull this forward toward the front of the handbrake as per the grip and this too will slide over the shaft. Again refitting is a reversal.
Darren