There’s a 4th orange screw to be removed on the STEP1 image. It’s located on the top right corner of the projector body, if looking at it as shown on the photo...STEP4 image - all 3 plastic latches at the top panel are damaged. That’s why at the shown case, the front panel goes off easily.If the projector has never been opened, it is actually very hard to remove the front panel. One can release the latches with thin tea spoon (f.ex.), operating it with caution, over the front grill.

To remove and later disassemble the lamp, you don’t need to remove whole cover. Just open the lamp bay door and follow the steps starting  from 6!