The final two tabs can be more difficult to release. Viewing from the front, they are located in the back left and right corners of the printer.
The release points for the tabs are located in holes on the depressed area of the base (darker piece).
Use the mini screwdriver to pry out the tab.
Use one of the plastic tools to keep the tab pried out. Once it releases push in towards the printer (viewing from the side) and pull up on the case.