It's not a wax seal like a house - it's a rubber seal. They're usually installed on the toilet, which rests on a flange to which the toilet is bolted. The toilet is easy to remove - like a house toilet - 2 nuts.
Your bowl being loose from the base could be an issue depending on what's happened. I've read - but never experience personally - that early Dometic China bowls can break loose from the plastic base. Hopefully you'll find that you can just tighten the clamps. I have a new Dometic China toilet and there are clamps that you can tighten from underneath. Again, I haven't had to mess with it and I'm not sure you should have to mess with it.
To make a long story longer, the first new Dometic 320 I bought was apparently dropped from a tall building by UPS. The China part was dust. I kept everything else, though, as the seller didn't want the broken toilet back. If you have a similar model I can post pics of what the clamps, base and o-ring look like. Let me know...