Need instructions or video on how to replace a huma reg in A pistol marauder

http://foto.huma-air.com/foto/installation%20guide%20p-rod%204.0.pdf

1578802665_2157339305e1a9de960b0b0.30906923_20200111_201729.jpg

 
OP, are you talking about the plenum spacer? Some have it in there and some don't. You will see it all the way back there up against the block. It is thin so you will need to make yourself a tool to hook and pull it out if you want to get the Huma installed there in its place.. Otherwise things will not line up and you will not be able to seal the air tube.