The Land Rover LR3 Pollen Filter, also called a Cabin Air Filter is located behind the glove box. The Pollen Filter is easily changed without tools. Land Rover recommends that you change the pollen filter at an interval of 15,000 miles. If you live in a dusty area, it would be wise to change the cabin air filter more often, perhaps every 10,000 miles or twice a year.
I purchased this pollen filter from amazon for around $12 (April 2017) you can buy the filter here: http://amzn.to/2oJo24u
Please note: In the video, I misspoke about how to remove the pollen filter cover, the tab is pressed towards the driver side, not down.