This video shows how to install the Delta stem riser. It is important to follow these steps in the sequence illustrated. You will need a 5mm allen wrench and a 6mm allen wrench.
The bolt that drops in from the top should be snug, but not overly tight-- its job is to compress the bearing system for the steering column (known as the "headset").
The 2 horizontal bolts should be QUITE tight, as they finalize the connection between the handlebars and the steering column itself.
The video below was shot in real time, and this can be done in about 5 min.