Hard to get to Intake manifold nut

I need some advice on removing the intake manifold. Do I need a special tool to get to the lower middle nut on the intake manifold? I can see it but I can't get any turn on it. All the others came off nicely same with the exaust manifold. Can you believe all this just to clean out the EGR passages. They are clogged solid all the way from the EGR valve thru the intake manifold, the head and the exaust manifold.

Use a 12 metric wrench after you took out the EGR assemble, have patience it will fit in there, unscrew in small steps till you can take it out by hand , I did it at least 5 times so will u 2.
Make sure you use a thin walled wrench that s the secret.