Put on a pair or rubber gloves so that no germs or contaminants will be transferred to the parts of the tattoo machine, and then to your clients' skin.
Pick up the tattoo machine's frame, with the coils above the lower part of the frame, and insert the tube upwards into the hole with the slanted part of the tube facing forward. Loosely tighten the tube clamp next to the frame's hole with your hands because you will have to make adjustments once the needle is inserted into the tube. The tube's point should be pointing downward when inserted.
Slide the pointed tip of the needle into the upper hole in the tube carefully, and then slide the rounded tip of the opposite end -- the eye -- onto the armature bar's metal peg. Make sure that the break in the eye of the needle is facing to the left of the machine. The metal peg will be directly above the tube's hole and attached to the bar that reacts to the rear spring. Slide the rubber grommet over the rounded end of the needle and the armature bar's metal peg to hold the needle securely in place. Loosen the tube clamp and slide the tubing to adhere to the length needle you are using, then wrap the rubber band around the needle's stem and the back side of the frame twice. This will also keep the needle in a secure position.
Attach the clips that are attached to the power cord to the two binding posts on the back of the machine, then connect the other end to your power supply unit. Make sure that the clip ends of the cord are connected securely so that they do not come loose when operating your machine.
Plug the power supply's foot pedal into the jack labeled "Pedal Control," or something similar, depending on the particular unit you own. Once you power on the power supply unit, you will be ready to begin using your machine on your next living canvas.