i'm not sure why you don't wanna just crack the drain plug and drain some fluid back out, it's the simplest and easiest way to get it done. it's actually probably easier than disconnecting the drain hose, cuz unless the vehicle is running, you probably won't get much more fluid out than what is in the drain line. my suggestion is to buy another quart of fluid and drain out a lil more than you think it's overfilled by (using the drain plug) and check and refill in small amounts till the level is correct.
God Bless.
God Bless.