how can i remove the egr valve from my vauxhall zafira2003dti?

Hi i have the same problem with my Zafira 2.0 DTI 2003 Engine Electronics warning light comes on (small spanner symbol) when first starting the car the light comes on, goes out after a minute or two, I agree that it is probably the EGR valve,I have try to remove this disconnecting the pipes and the two torx bolts holding it on.but still dosn't moves.Even gave it a little tap with a hammer still dnsn't move can any one help thanks