Once you've gone all around the body and popped open all four teeth, it should be trivial to pull out the cover

Notice in the 1st and 2nd photos the location of the teeth, you'll need to match them with their corresponding grooves when assembling

Notice in the 1st photo, in the red square at the centre, the engine's blades are exposed. Do not insert your fingers or any other items in there.

Also notice in the 2nd photo circled is the guiding indentation. This indentation needs to match with its corresponding groove at the front of the device, right behind the Eufy logo, when assembling