Repacking SPD bearings

I've got three pairs of these on different bikes, all of which are now feeling a little gritty. I've tried getting in there to give the bearings a clean and repack, but I think there's a custom tool you need. Can't find it anywhere though. Anyone done this?

Really don't want to buy new pedals just for lack of a tool if this is do-able.

http://www.parktool.com/repair/readhowto.asp?id=84

looks like your pedals dont need the special pd-40 tool; nice.

Cheers for the link, but I'm a bit confuzzled - that's for a road pedal. Mine have the same notched black ring on, which is the bit I can't get off.

Yeah, there is a special tool - it's a little grey plastic disc. IIRC, Madison remove the tool from the packaging - if you buy pedals from outside the UK, you get one.

http://www.sjscycles.co.uk/product-Shimano-Shimano-TL-PD40-SPD-Clipless-Pedal-Axle-Removal-Tool-5968.htm is the thing.

Wow, that's cheeky. I've bought three sets and never got one.

:(

So, buy that, whip the pedals apart, clean and regrease, then they're good as new?

That's the theory, anyway...

The Spd-M540 need a 19 (if I'm not wrong!) spanner, no special tool. Some of the road ones (I forgot the codes...) do need it.
The tool works best if held in a vice, and don't take apart the whole axle assembly! Those ball-bearings are very small ;)

I did it without the tool, but it was years ago. I think I just used an adustable cone spanner (it's got many notches).