Can you provide more details on exactly what you want to access? The transmission case is a solid casting and only the top cover and a couple of drain and fill plugs remove. The top cover is held on by several bolts accessed from the top. If you have an overdrive, that is a separate casting bolted via an adapter plate onto the rear of the transmission case. The only way to access the internal components in that unit is to remove the entire overdrive and work from the open front of the case.