Here is a look at the locking assembly that you disengaged during Step 2.

Next, use your spudger or other opening tool to push upward (towards the screen) on the small plastic tabs that are located on the top of the docking station guide ports. This should push the screen away from the frame and provide you enough room to insert the flat side of another spudger to start freeing the bottom of the screen from the case.

Work the flat end of your spudger along the bottom edge of the tablet to disengage the plastic tabs from the locking mechanism inside.