Mk1 DMR V8s have a 12mm locking nut you will need a socket to undo (and a fairly low profile one, not all my sockets are skinny enough to fit).
Sod it, saves me typing it out:
http://steveukmtb.wordpress.com/dmr-v8-pedal-overhaul-cup-and-cone/
My V8s are over 10 years old thanks to regular servicing (and an allergy to mud).
Contrary to opinions above, it’s a piece of piss.
Cartridge bearings can be difficult to remove without the correct tools. As they tend to be pressed in, it is easy to damage the holding body by failing to pull them out straight.
Having said that, if your pedals are knackered what have you got to lose? :D
Always buy replacement bearings from an engineering shop rather than a bike shop. They will be the same but a fraction of the price.