Instructions
Log into your Battle.net account and click on the Account Management link. Scroll down to the bottom of the page and hover over "Character Services" until the options appear, and then click on the "Race Change" button.
Select your character from the list on the left side of the page. Your human male character must be at least level 10 to be eligible to change into a male Blood Elf. If your character is a Death Knight, you must be at least level 60 before changing to a Blood Elf. Read the Terms and Conditions and click on the "Agree and Continue" button.
Enter your payment information on the next screen and check the box to accept the Terms of Sale. Submit your payment and wait at least 30 minutes before logging into the World of Warcraft game.
Log into the game with your email address and password, and click on the new button next to the character's name. This allows you to change the character a human male into a male Blood Elf, as well as alter his name and appearance. This process is very similar to the initial character creation process. Click the button labeled "Click to change your character's race" to complete the change.
Log into the character and examine your interface for any missing mounts, items or gold. Humans and Blood Elves are both eligible for the same classes so all of your attacks and spells should remain the same. Race-specific mounts will be transformed into their Blood Elf equivalent, and all items should remain either equipped or in your bags as they were before the change.