I used two nails or two 2-3mm allen keys in the tensioner and then put a spanner or screwdriver in between the two and twisted to apply some tension, then locked the tensioner with the bolt. After removing the pin from the auto tensioner, spinning the motor a few times then letting it sit for a bit the shaft pin hole wasn't too far out from the body pin hole. It takes a few goes to get it bang on but you can feel what works and what doesn't.