The bowl has come loose from the base of the toilet in my motorhome. The bowl is porcelain and the base (with the flush valve) is plastic. Looks like I will have to remove the toilet and turn it over ...
Here you go. There are 4 bolts that you access with a looooonnng screwdriver or a 5/16 nut driver from underneath. I'd be careful how tight you go. As you can see clamps are plastic. I'd guess they're pretty easy to strip.