Waterco F600 top mount multiport valve sand filter - removing the valve

Hi guys,
I have a F600 Waterco top mount multiport valve sand filter and I cannot figure out how to take the valve off the filter body to change the sand. Can anyone please give me some ideas?
Thanks!
p.s. I have pictures of it but I do not know how to add attachments...

NOTICE TO OTHER POSTERS: This guy is in Australia, so don't give him US-only advice, please!

According to the schematic on this page
http://www.aqua-man.com/schematic.asp?kc=S2202
that filter valve is either a clamp-on or a threaded style. Sounds like you have the threaded model, in which case the whole valve unscrews from the body of the filter.

I've never worked on one of those, so I'm not sure of the best way to do that -- possibly, judicious use of a strap wrench, like this one
http://www.amazon.com/OTC-7206-Multi...9894476&sr=8-2
would work.

Thanks mate. I have also emailed Waterco to find out the best way to take it off also.
Would I need some thread tape to re-seal it afterwards?

My guess is that it has an O-ring seal.