i see no one has answered over the past two days, so I'll add what I know.
I never tried adjusting it with the emergency brake applied, so am not sure if the mechanisim will tighten up, but I would think that it would loosen with it applied - but just a guess.

The star adjuster moves in opposite direction for the left and right wheels, I don't recall which way for each. Usually I back off the friction then tighten up and at the same time rotate the wheel/tire until it binds then backoff till it is free.

A LED or flourescent light source (flashlight,workshop light) can illuminate inside the lug hole to see the star adjuster. I've never been able to illuminate it with an incandescent light - figure that one.

I wouldn't like lifting a car in neutral with the rear wheels up. And don't advise it - too dangerous. But when I DID -stupidly enough- I placed a spare tire under the sill between the wheelbase, and chocked front/back of both front tires, and found that a rubber mallet, wedging the rubber head in there acted well as one of the four chocks. I also used a floor jack ( with a rubber pad so not to scratch the diff ) placed under the rear diff just slightly lifting upward on the rear drive unit.

But in the end rent a bay or have someone place the car on a lift to adjust it, and at the same time take the tires off and inspect stuff.