Wiring an insert-type socket or dimmer is a fairly simple process
First, with any electrical work ALWAYS ensure the power is OFF.
Step 1.) Line up the wires with the proper terminal.
Neutral Wire is Ribbed connects to the silver terminal
HOT Wire is Smooth connects to the brass screw terminal on the dimmer.
Step 2.) Insert the wires into their proper terminal hole.
Step 3.) Tighten the screws to Secure each connection tightly, reassemble the socket or dimmer, and restore power.
REMEMBER!! Always follow safety guidelines when handling electrical work.