You have to use a 7/16 wrench not ratched one, I got at at sears for $2
The first turn is the hardest (opening it) and is easier by pushing the metal tubing a little which is connected to the CDV
Also dont waste your money buying a modified cdv because all it takes is a thin drill bit. Basically just insert the drill bit through the smaller hole in the cdv. Just put pressure while the drill bit is turning and the restrictor will just fall out. Dont worry you wont break anything.
after the restrictor comes out, just clean the cdv and blow air through it to get any plastic fragments out.