The most important thing to remember at this point is to make sure that the Stages crank you’re installing goes on at 180 degrees to the drive side crank. It sounds ridiculous but if you’re not paying total attention it’s definitely possible to get it wrong, which would be rather irritating. 

Gently push the Stages crank onto the axle and when it won’t go any further, put the star bolt (preload adjuster) back in and tighten it until there’s no play in the crank, but not so much that the crankset won’t spin freely.

After that, tighten the two 5mm allen bolts up to the recommended torque (Shimano suggest 12-14nm). It’s best to use a torque wrench for this, even if it’s a fairly basic one like the model in the picture. And with that – boom! – installation is complete.