This video shows how to install the Delta stem riser. It is important to follow these steps in the sequence illustrated. You may need to pull a small amount of wiring out of the frame--shown in the video-- just be mindful as to not be too forceful. 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.