Stilkus

Hello,
Just bought an Rx400h and after driving like 2000kms discovered the head gasket Was shot and it is getting worse everyday. I have the 3mz-fe engine. I couldn't find any Information regarding head removal. Is it possible to remove the rear head with the engine inside the car? I believe it is similar to the RX330. I am located in Germany and we don't get that much help with Japanese cars here. Any info would be helpful.