Can i delete a premade World of Warcraft character so i can download another one?

i maxed out on the amount of characters i can download, and i want to know if i can delete one to download another. i have a dk, warlock, mage, and a hunter, and i wanted to delete the dk so i could download a warrior. if i delete it, will i be allowed to download 1 more, seeing i will still have 4? or do i have to wait for them to reset the count?