Instructions
Log in to your "World of Warcraft" account and choose your hunter character.
Press "N" on the keyboard to bring up your character's talent tree.
Click the "Pet" tab located on the right-hand side of the talent menu.
Click a non-greyed out talent box to place a point into that talent. As you spend points on the low level talents, you will open up higher level talents for your pet.
Click "Assign Points" to assign the spent points to the chosen talents.