New tranny with downshift clunk. Too little vac so I am adjusting. Just adjusted the lever on the vcv so the gap is 0.5mm at WOT per Steve Brotherton's article. Now he says to adjust the nut under the plastic dome to get correct amount of vacuum.

Cannot figure out how to remove the plastic dome. See the dome in the pic at the arrow. I assume there is an adjustment nut under it but the dome has not been out since 1981 and I do not want to break it.

Is this just a press fit of plastic dome that gets pried out with a screwdriver or how do I remove it?

Already my vac (per mityvac) is down from 9psi - which was too low- to 6" at idle; due I expect to my adjustment of the lever to 0.5mm. So I really have to make the dome nut adjustment to get more vac. (Some call this entire part the vacuum control valve but I found it in parts listed as injection pump vacuum control.)

Help appreciated; how do I remove the plastic dome?

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