You can do it yourself. The front is much easier to replace than the rear because there's more room. You have to prop the tank up, take the airbox off and possibly the carbs to get to the front cct. Next, undo the cap bolt and get a small screwdriver to keep the tensioner "unwound" while you undo the two bolts holding the the old tensioner. You may have to buy a new gasket depending on if you can salvage the old one.