I am replacing a 10 year old electric oven. There are actually two ovens I am replacing. There are four wires times two coming out of each conduit for each of the ovens. They lead to the circuit panel where there are 2 (two) 30 amp breakers connected to one another for each oven circuit. So 2 sets of 2x30 breakers. My oven model is rated at 3.6kw so the install instructions say it should have a separate 20amp breaker. Can I just connect it to the 2x30amp breakers or do I need to install lower, 20 amp breaker?
Simple. Replace the breaker for that oven with a 20A version since that's what the instructions call for.
You're lucky that the wire is almost certainly large enough for 20A. Going down in breaker size is FINE. Going up rarely is.