How to remove the EGR valve. 1.5VHGOGC engine on 1994 Toyota Paseo

Idle speed decrease to around 500RPM then cut off after drive around 10 miles. Wanted to remove to check EGR valve but I could not remove one nut that I copuld not reach with any normal handtool. Any suggestion? Did I do the right thing by checking the EKG valve? Any help would be appreciated.

Asked by for the 1994 Toyota Paseo