Thanks The Bodyman,Veilside.
Stu, pretty straight forward really.This is the process I used which worked for me as I struggled to find a clear guide to follow.
Firstly you need to remove the oem leather cover on your handbrake.I did this by running a scalple down it but decided to use a cutting wheel on my Dremel as it was quicker that way.Once done with a bit of force you can peel the leather off completely.
Next step was to prise off the rubber surround at the base of the handbrake.I think it is glued on so start it off with sliding a butter knife under it and then pull it hard to prise it off.
Next step is to test fit the new cover.Because of the flared design of the rear of the handbrake its normal to have to cut a 2cm by 1cm opening on the underside rear of your new handbrake cover so it can push back far enough for the button at the front to protrude and function.I did this by wrapping the new handle in a cloth,putting it in a vice and jigging it out with my Dremel.
Next job is refitting it and marking through one of the holes in the handbrake handle onto your handbrake to drill a hole to secure the new handle to the brake with the grub screw supplied.Nearly there.
Finally.You will need to buy a handbrake gaitor.Got mine for a tenner on eBay.Refit the rubber handbrake base with superglue.Slide the gaitor over the brake.Screw the handle in with grub screw and pull the new gaitor up and over it.
Job done.Might not be the best or right way but it worked for me.