I've never done it on the T&C but I would assume that in the trunk/rear of the van there would be removable interior panels that would expose the tail light assembly which would be held in place by plastic clips or small screws. Once you remove the clips of screws the assembly should pop out.

2002 Town and Country  Right brake light will not light when brake's depressed. I changed the light and it still won't work. Turn signal works so I know the bulb is fine.