I would never touch plumbing, unless you're proficient and know what you're doing. If I'm doing a job where there is only 1 toilet I have my plumber come and take it out in the morning and put it back at night for the customer, and he builds that into his cost (although we try not to work too far from home). That way he's responsible for the water, and I don't want to be. What happens if you do, and a valve fails overnight and flood downstairs for example. I don't want any association with that, thank you.