glow plug warning light

Can anyone advise me on how hard it is to change the brake pedal switch on the wifes 04 passat.Done a bit of searching on the site(the glow plug light is illuminated on the dash)checked the brake lights and none of them are working(inc. high level one)I understand the switch is about £12 ish and thought i'd have a bash at fitting it myself if it's not too difficult.Anyone done one before? Hints/tips most appreciated.Thanks in advance.

If using a genuine switch, rotate the old one out anti clock and fit the new one the opposite way around, do not press the pedal down with the later updated switch. I suggest you buy two as I often break one fitting them, they are rubbish!

Concise instructions HERE
From another forum (Mods remove if inappropriate)