My Haynes manual says to use a joust to lift the weight of the motor off the mount. Is it possible to put 2x4s under the engine and use a jack to push it up?

 

On the older models anyway, you should only have to detach the exhaust pipe to R&R oil pan. The motor mounts would stay attached.

You couldn't support the engine from the bottom and remove the oil pan because the oil pan covers the whole bottom of the engine.