How do I get the front off

How do I get the front off to access the components that are behind the knobs?

The instructions are attached.

Gene.
PSC - PDR Valve and Potentiometer removal.pdf (184.0 KB)
PSC - PDR Valve and Potentiometer removal - 2.pdf (146.0 KB)
PSC - PDR Valve and Potentiometer removal - 3.pdf (162.6 KB)
PSC - PDR Valve and Potentiometer removal - 4.pdf (177.0 KB)