Thanks to everyone, followed the intructions on the dcioffice link. Really straight forward. The Egr took some brute force to remove, absolutely caked in soot and tar like deposits. Left it in a pot of engine degreaser whilst I scooped out lumps of carbon and "tar" from the valve body. Also took the opportunity to remove and clean the "hockey stick" inlet pipe which was full of the same crappy deposits.
Seems to have significantly reduced the amount of smoke I've been kicking out before. Hopefully the mpg will come back up too. (dropped from a consistent 60mpg to 54mpg, in the last fortnight, same driving style and same commute to work)
Thanks again everyone,
Cheers, Leigh