piss easy, just remove the trim around the handbrake lever, you can do this without removing the centre dash stuff but its easier if you do remove them (the stuff around the ashtray).
then you will see a bolt with a nut on the back side of the lever all within the car. simply tighten this up. and voila, you need to tighten it up so its locks after 4 clicks.
Passed mot, it may be that one of the cables is knackered in which case u need to buy one. There is a how to on this site.