Air filter removal question

Living out in the woods our cars a plagued by mice. They especially like getting into the air filter boxes. Well, I usually put hardware cloth in the air box to stop them from making a nest out of the filter element.

I’m trying to get my air filter out of an 2001 XC and am having troubles, perhaps someone could help. I’ve unsnapped the three clips in front and disconnected the sensor wire connected to the air intake. But the cover won’t come off. It seems that there are three tabs in the rear that slide out. The tabs at each end move but the middle tab isn’t budging.

Any hints and/or techniques to removing the air filter cover.

PS: One of the front clamps broke while I was re-closing the cover, very brittle and thin plastic used in the clamps!

Thanks