Drill or cut a hole through the center of the wood for the power cord. The light will be attached to one side of the wood and the cord will go through the hole to come out the other.
Wire the power cord onto the light fixture. If the hole you made through the wood is small, string the cord through the hole before attaching it to the light fixture (otherwise you may not be able to fit the plug through the hole).
Securely fasten the light fixture onto the wood with screws.
Screw a light bulb into the socket and plug it in to make sure it works.
Cut a hole in the center of the bottom of the can that's about 1” across. This can will fit over top of the light with the open end down and the end with the hole at the top. The angle brackets will be used to fasten the can onto the wood so you need to make small holes at opposite sides of the open end (now the bottom) so you can screw the angle brackets onto the can.
Once the brackets are screwed onto the can, place the can over the light and fasten it onto the wood by screwing the other 'arm' of the angle brackets onto the wood. If you plug it in now the light should shine through the small hole you made in what is now the top of the candler.
Since the top of the can is hard, we need to make a soft cushion to lay the eggs on so they won't be damaged. To make the cushion, roll the cloth into a sausage and interleave the two ends to form the cloth into a dough-nut shape. The hole in the middle of the cloth dough-nut should be just a little bigger than the hole in the top of the candler.

Now place the cloth on the top of the candler and your candler is finished! To use it, simply plug it in and place the egg you want to examine on the cushion. The light will shine through the hole and into the egg.
If you want to get fancy, you can splice a switch into the cord so you can leave it plugged in and still turn it on and off.