Fixing rotarr engines is dead simple, mazda have made it pretty easy.
The engine and transmission drop out from the car very easily and can be done in under 2 hours with a lift, changing the plugs is pretty much the same amount of ass-pain as a fwd v6 engine where you have to teardown the intake manifold and also wiper cowling and even engine mounts in some cars to remove the rear bank plugs.
Heck
Even plugs on the new bmw engines take a few hours because you have to “deconstruct” the wiper cowl, air ducting, wiring etc to get to the coils and plugs.