Leatherworking is a profession that can use Disassembled leather to create new leather armor.
To learn Leatherworking, you need to visit a Leatherworking Trainer and purchase a Leatherworker's Training Manual.
Leatherworking is a crafting profession complementary to Disassembling. The goal is to have as many positive values as possible in the overall outcome of the balance of complexity, quality and success rate. By a good mixture of these one could dictate either or not they would have the ability to increase their skill a higher point or not or even dictate either or not if the item is a higher quality item in terms of uncommon, rare or junk. The mechanics behind this are not yet truly understood however, due to the sheer complexity of it.
You need to purchase a Leatherworker's Tool Belt from the trainer.
To begin creating items, right-click on the Leatherworker's Tool Belt in your inventory.
To increase your skill, you must produce items, that would grant you the highest amount of profession points. For this to work, you must either, have a secondary profession of Disassembling or, you must purchase items, that are needed for you to create something successfully, such as , Damaged Leather Patch, from the Auction House, which is located in Yasker's Tower.
Eskarioth's in-depth crafting guide, click here.