1. Make sure the setup is correct. The non-movable part of the yoke should have the factory side of the die. The movable ram should hold the butt or finish end that you are squeezing. You may set this up differently as you gain experience.
2. The rivet you are squeezing must no be too long. Too short is easier to rivet than too long. When learning make sure the unfinished rivet is no longer than 1-1/2 times the rivet diameter. In other words, a 1/8" rivet should be sticking through the metal 3/16" before squeezing.
3. Place the rivet into the hole, place the factory die side of the squeezer set on the rivet and hold a slight pressure to keep the rivet firmly in the hole you are preparing to squeeze.
4. Hold the squeezer in alignment with the rivet and activate the throttle very little. This will move the ram slowly toward the rivet butt side. When the die touches the rivet, continue pushing slowly to start squeezing the rivet and forming the butt. You may stop at any point. An aluminum rivet can be squeezed further at different times.
5. As the rivet starts to form and everything looks aligned continue squeezing the rivet by activating the throttle more. Slow is easier, speed will come with practice. Once fully squeezed the butt end of the rivet should be formed and should be about 1-1/2 times the diameter of the rivet. In other words the shop head (finished end after squeezing) of a 1/8" rivet should be about 3/16" in diameter.