I accidentally peed in a toilet that I forgot was incapacitated (the water for it was turned off to do some piping work, but there's still water in the bowl), and I need to get it out of that toilet and into another one (the nearest other toilet is about 30ft away). What should I do?
You say the "water is turned off to do some piping work." I assume this just means the water is off to this toilet, and the toilet's drain pipe still connected to the sewer outlet. Is this so?
Then the solution is really easy - you can do a "manual flush." Just take a bucket of water and pour it into the toilet. It will flush on its own if you put about 8 L (two gallons) into it. Maybe use a bucket or a large cooking pot or a garbage can. Pour it all in at once! The urine - and anything else in the toilet - will travel to where it normally goes, without any physical contact.
It's not the end of the world--But it's not much fun
First, urine is not likely to cause disease, though it has an objectionable odour and it comes out of the waste-end of our body. It can be handled without risk.
You'll need an absorbent and reusable rag, (You'll not want to keep it for very long, afterward.) A pail, and a pair of gloves (optional but recommended).
As you can guess, it's a matter of soaking-up the liquid and wringing-out the stuff into something to carry it to toss.
You'll have to rinse it out at least once with fresh water or with baking soda and vinegar (two heaping tablespoons into a quarter-cup of white vinegar and a cup of water).