The filters are quite easy to remove, clean and put back. No need to replace unless they are damaged. I did mine in about 1/2 hour which included cleaning time with the air hose and shop vac. Mine was really plugged to the point where I was getting almost no air through the vents. The downside was that the blower motor resistor blew and I had to resolder it. Bought a new one but the repaired one is holding fine after about 4 months.
The factory manual details the actions. The Vitara manuals are available somewhere on this site in PDF form. There are 2 pages and I copied the first page into a word doc. The second page is only one bullet telling you to put everything back the same way you took it out.
Can't figure out how to attach MS word docs to this! If you want to send me a quick email, I will return the doc as an attachment.