Emissions system leak

What is your question?

I found that my vehicle has a "purge valve" it is an in-line valve having to do with the emissions system, I replaced this part to correct a vacuum leak that kept my engine light on, this worked for a bit and the light came on, I also replaced the gas cap, again the light came on, I have noticed that the rubber hoses under the vehicle are worn out and probably need replaced, do I have to drop the fuel tank and pull the engine to replace the pair of hoses, they go from the engine, to somewhere above the fuel tank... How difficult is it to remove the fuel tank?