Hello there. I am somewhere at the same point as you. If I understand the process correctly, the first thing you want to do is make sure your exhaust cam chain has maximum slack. Loosen the lower and upper tensioner lock nuts. The lower may be all that is needed. Then pull up on the long exhaust cam chain. You should see the inner slide of the tensioner slide upward. This is the beginning of slack... Next find a pair of vice grips that fit perfectly inside the inner slide of the two piece tensioner and outfit the jaws with duct tape or gorilla glue tape(I love that stuff). You'll need to grab that inner slide piece and Heman that MF all the way up!! Lock the lower tensioner lock nut. Now you should have maximum slack.
Loosely install the exhaust sprocket onto the cam (no bolts). Then pass the cam and sprocket (lose) through the exhaust chain (maximum slack). Position the lobes correctly, position the dot indicators on the exhaust sprocket with the head. Install the exhaust sprocket in it's final assembly position on the cam with the bolt holes aligned.
**Verify 1.4T, sprocket dots and cam lobes are all PERFECT POSITION or you will be off a tooth and have to remove the cam chain and repeat installation all over again...
Begin installing the cam chain IN THAT EXACT ALIGNED LOCATION. DONT LET ANYTHING MOVE.
The chain should only install about 1/3 to 1/2
**While keeping the chain meshed with the sprocket where you just double checked all the alignment marks, slide the sprocket and chain off the cam boss where it is installed. Don't let the chain slip off from the sprocket!
**Take a moment to look at the groove that they cut into the cam boss...looks as if it was designed that way on purpose.
With the sprocket slightly lower, fully install the cam chain (some prying, stretching and pushing of the chain needed, but the chain, at maximum slack and not installed on the cam should install onto the sprocket.