I looked up the Nissan service manual, and it only mentions that one has to open the filter door to change the in-cabin microfilter. So, that’s what I did today. I managed to change the filter without disassebling anything else. The only problem is that the opening is smaller than the filter, and one has to squeeze the filter to push it in. I am not sure if I might have damaged the filter forcing it in this way.
The filter I used is FRAM CF11173. It seems to be identical to the original Nissan part. Both have charcoal in-between. FRAM claims to have ARM and HAMMER baking soda to absorb the smell.
It cost me about 22 dollars including shipping, bought through eBay from B & C Auto Parts Warehouse.
I meant to post some pictures here but I do not know how. I tried just copy and paste but it did not work for me. Thanks for any help.