Removable grilles for easy cleaning?

We just figured this out ourselves. There are four (4) screws on the back of each fan that when undone it releases the grill for cleaning. But the fun part is getting the screws back in to the little holes. But all in all we got it clean...

I used tweezers to put the screws back into place.....   Also...the screws are on the back of each fan head between the back grills....it's hard to see...but after CLOSE inspection you'll see them.  
Wash the front grills in the sink, dry and put back into place.  I wiped the fan blades and used my dyson to clean the back grills.  Looks like new.