Let the shirt sit for a minute or two, to make sure the bleach can fully destroy the color (how does bleach suck color out of stuff? Isn't that absolutely terrifying?)
Then, take the letters off, being careful not to smear any bleach, and rinse the shirt in a sink for a minute or so, kneading it. Rinse it until the water running off the shirt is clear.
Now, put your shirt out into the sun to dry.
Go take a shower--it's a hot day.
The shirt will be dry by the time you get out.
It it's not, take another shower. Or write an instructable or something.
By now, it's about 2 in the afternoon--time to get to work. Put on your creation, and go dazzle your friends with your artistic ability!