So you go to Ironforge, and into the Tinkertown area. See High Tinker Mekkatorque? He's the guy with the green glowing goggles in the middle. Suspended in the air behind him - a seat! Lets get in that chair!
Step 1: Go stand on the forge North of High Tinker Mekkatorque.
Step 2: Facing DIRECTLY West, jump at the wall, and tap your forward button while you're mid-jump. You should be standing about at the second bolt on the wall.
Step 3: Regular wall jump a couple times up onto the ledge!
Step 4: Turn South, jump up on the little spindly thing holding up that seat!
Step 5: Turning East, back up a bit and jump at the back of the chair. If you do it right, you'll land either on top of the chair back, or sort of behind it. Either way, jump up and tap forward to get on the front.
Step 6: Let the bossing commence! Enjoy your throne!