Once you unscrew the caseback you should be able to see where the stem enters the movement. Right next to it there should be a very small dimple/button. If you press this in it will release the stem. There should also be two small tabs with screws holding the movement in place. Once you unscrew these two, making sure you dont drop anything into the movement itself, you should just be able to turn the watch upside down and the movement and dial will drop out.
if its a 7750 movement make sure the stem is pulled out to the date set position before removing the stem. It will save you headaches getting it back in after.