Ok, it's official, I'm an idiot. I just figured it out. They do just pull out, but they're very tight because it's new. I was too worried about breaking it. I still can't quite see the choking screw, though. If any one has any advice for adjusting it, please let me know.

Why do you want to adjust the oven burner?

It seems to be hotter than what the knob is labeled. I have a thermometer inside the oven, but it would be nice if it was closer to the indicated temp on the knob. It seems to be running about 50 degrees hotter, if my thermometer is accurate. I had the knob set to 350 and the thermometer was reading 400.

My limited understanding of the Berta gas oven is that the oven burner works like a cooktop burner and the oven has a lowest temperature usually around 275f (flame should be on all the time, at least on most models).
It might be best to avoid any adjustments right now and set the control knob to the lowest setting that keeps the flame on continuously and determine if the temperature is in the normal 275 ballpark and carry on from there.
Check with Bertazzoni after that. There may be other ways to adjust for better results.