Seeing as some of you were interested on how to do it and costs here is how I did it.
Now there are two ways of doing it but the first way didn't work so well with me, and that is to use a fine tiped jewelers awl/small pointy thing and prise the cap off, this way I managed to do two and it took ages, the glue on my LE was realy tough and on one knob I slightly damaged the plastic arround the pot.
The way I did it was different...
I removed all the knobs from the mixer; you will need 2 sizes of allen key for this as the big pots and the smaller ones have different size heads. I used a 1/16 allen key for the small pots i.e. balance and a 5/64 for the main volume pots.
I then got a drill and yes I drilled through the centre of the pot!
Once the hole has been cut I got a screw driver and pulled off the cap
Now all you do is glue the new caps on and hey presto!
I got the caps from Mario for about £14 inc postage to the UK if I remember correct.