Opening Cover for Air Filter?

Pony 7HP Briggs & Stratton Model: 13WN77KS01

The plastic cover for the air filter is on top - not the lower side like most others.

This model has plastic knobs on top of the mounting screws.

No matter how I turn & twist things I cannot get the cover loose -
and I don;t want to break it.

Is there a trick to these things?

Do I need to apply some lubricant?

Thanks!.

Attached Images

• enginetop1-sm1-cp1.jpg (220.8 KB)
• enginetop2-sm1-cp1.jpg (276.3 KB)