How do you adjust the flame on a Kitchenaid Superba Gas Range?

A homeowner does not "adjust" an oven that is set up to work on liquid propane (LP) so that it can be used with nautral gas. What must happen is that the gas jets in the burners must be replaced, and this is not generally a job for a homeowner. Call your LP supplier or the gas company to get the scoop. They are professionals who hand out information like this to folks like you just for the asking. They actually want you to call. That way you don't end up in a jam because you dove headlong into modifications that, if done improperly, can end up killing you and/or your family and/or destroying your home. Talk is cheap, so make the call.