The main fuel filter is located under the vehicle. On the drivers side about mid-point. It is mounted on the frame of the car. It is held in place with a strap mounted to the frame. It is a small cylinder with two hoses on either end.
No the tank does not need to be removed, the filter is located under the vehicle running alongside the frame, but if you have never changed a fuel filter before I would suggest having a qualified mechanic perform this, because when you remove the filter quite a bit of gasoline will pour out and can be dangerous. Shop time to remove and replace fuel filter for your vehicle is 1/2 hour. parts cost is $14 to $21
Here's a online guide for replacing a fuel filter on a Isuzu Rodeo which is basically the same as a passport and they use the exact same part number on the filter http://www.autozone.com/shopping/repairGuide.htm?pageId=0900c15280061f7a Hope this helps