It sounds like my '04 Expy with the 4.6L is configured like the your truck.

From underneath, go behind the plastic drip tray, look up and you'll see the base of the filter. Work a flexible head strap wrench between the filter and the drip tray. Move the strap wrench to the base of the filter and turn counter clockwise. Be sure to have a large enough pan to catch the oil from the drip tray and from the filter base as it will leak out both.

After the oil is drained, you can wiggle the filter down the drain trough. Apply some oil to the rubber ring on the new filter and reverse your steps.

When finished, wipe all the old oil from the flat spots on the drip trough, add new oil and your finished. It's a piece of cake I promise.