The process for upgrading items is simple. Drag the item you wish to upgrade over to the item slot, then hit the upgrade button. Only items that are 458 ilvl or higher can be upgraded. Blue quality items can be upgraded once for an 8 item level increase for 1500 Justice or Honor points. Epic quality items can be upgraded twice with a 4 item level increase per upgrade for 750 Valor or Conquest points.
Once an item is upgraded, there's no way to get them refunded. Choose them wisely! If you're not sure what to upgrade first, I would suggest focusing on your weapons and trinkets. For most classes, you should notice a slight increase in your character's performance.
Mists of Pandaria is here! The level cap has been raised to 90, many players have returned to Azeroth, and pet battles are taking the world by storm. Keep an eye out for all of the latest news, and check out our comprehensive guide to Mists of Pandaria for everything you'll ever need to know.