Where is the evap hose on a 02 ford taurus

That's a system that includes a series of hoses and valves, not just a single hose. If you suspect a leak, about the only way to find it is by using a smoke machine to inject a white non-toxic smoke at 2 psi, then search for where it's seeping out. You might be able to rent or borrow this machine from an auto parts store.

How did you conclude that you needed to "change a hose"?