Changed the pollen filter on my GS450h today and took some pics in case it helps other members. If nothing else it can save you £xx paying a dealer....
It is a very simple and straightforward job, only requiring care and heeding the very first step so you don't break the system - if you don't follow step 1 to the letter then you will damage the filter cover door which is an expensive and awkward fix
1. turn engine on, switch aircon to recirc only so that the only button lit is the recirc one:
Then turn off engine
2. open the glovebox, empty of all 'detritus' and take a firm hold on the shelf and shelf support in the lower centre (all one assembly) and gently pull out of the glove box and place to one side
3. you will then see the filter door cover (scuse the muck, needs a good hoovering)
4. push up vertically all the way along the top edge of the door until a gap apppears at the base
cont. below