As far as actual replacement goes, you flip the unit upside-down, unscrew a knob, and then pull the inside section out. The pre-filter wraps around the main one and is secured in place by velcro. It’s not as elegant as the 1st one, but it’s pretty simple nonetheless. Once you’ve replaced/vacuumed/etc, it just slides back… Continue reading ENERGY STAR Certified Room Air Cleaners