my vapor canister is faulty and needs to be replaced. how do i do this

The canister is under the body of the vehicle near the fuel tank, covered by a shield. If you do not have access to a proper lift to raise the vehicle, and tools - I would recommend having a skilled, equipped technician near you approach this repair. Also, what testing of the evaporative emissions system has been performed where you have verified the canister has failed in some way? Testing must be done - no "code" can condemn a part.