I wish you the best. I'm not going to get into the 'how' to do it as others here have given lots of opinions on that.
I want to warn you about drinking so much water that you 'float'. My sister has always been a huge water drinker. Last fall she started acting really strange, had memory issues, lots of confusion, inability to speak and other things.
She also has seizures and had a mild one when she was out and alone so someone called 911. While in the hospital they discovered that her sodium level which should be 134-145 was in the low 20's. We learned that you can die from dangerously low sodium and that there are many symptoms.
I would like to suggest that you read about the dangers and if you see any that you have, get your blood work done. The DRs. told her that it's not uncommon in people who drink too much water and that YES you can drink too much. it flushes the good things, like sodium, that you need out of your body. She now drinks some water but also Gatorade and other sports type drinks that have salt in them. She struggles with keeping her levels up.
Best to you.