NeoPixel dots have the word IN printed on the back of the pixel on one side. It's hard to see. If you can't tell, and you're just not sure, lay the pixel dots face up with the strip flowing away from you. If the red wire is on the left, you're holding the IN end. If it's on the right, you're holding OUT. Or look for the male connector, it's usually on the IN end.

Get out your bolt-on kit. It comes with four screws and four bolts that are just the right size to fit through the Circuit Playground's mounting holes. We'll need just three of them (so if you dropped one on the floor and lost it in the carpet, no worries).

Once you've found the IN end of your strip, cut off the connector. Pull the three wires apart a bit so you have a least a half inch of free wire to work with. Then use your wire strippers to strip about 1/4" of shielding off each of these three wires.

Twist the stripped wires together. The red wire goes to VOUT, the middle wire to A1, and the remaining wire goes to GND.

Now, stick the bolts through the holes and secure them with the little nuts on the back. It helps to use a screwdriver to tighten them down. You don't need them to be super tight -- finger-tight is fine. The idea is just to hold the wires firmly in place against the pads.