Clean the vase and completely dry it. If any moisture remains in the vase, it will form condensation inside the lamp -- not a good thing to have near electricity.
Determine which part of the vase will be the back of the lamp. Make the hole that the plug wiring runs through near the base of the back of the vase. Place masking tape over the area for the hole.
Fit the diamond drill bit into the drill. Make a hole in the lamp base that is large enough to accommodate the cork or rubber grommet and allow the cord to pass through. A 1/2-inch bit will usually do the trick. Drill a hole through the masking tape and the vase. The masking tape helps to protect the vase and keeps it from cracking around the hole during the drilling process.
Remove the masking tape and insert the cork or rubber gasket from the light kit through the hole. The cork or rubber gasket protects the cord from being cut by the edges of the hole. Thread the plug wires, also from the kit, through the gasket or cork.
Seat the light socket on the neck of the vase. If the socket is much smaller than the vase opening, use the support rod that comes in the kit. Attach the plug wires to the socket base as indicated by the kit directions.
Attach the harp to the socket. Fit the ends of the harp into the two brackets on either side of the socket. The harp supports the lamp shade. Put the correct wattage light bulb in the socket. Plug in the lamp and test it. Place the lamp shade over the harp. If there is a finial included with your kit, use it to secure the lamp shade on the harp.