Yes it has been covered many times, although I wanted to make sure.
A simple yes or no answer will be fine.

1. I have a 9005 Socket w/ 9005 Bulb (Silverstars)
2. Remove two plastic guides off inside the socket.
3. Remove 3mm of plastic off the exterior of socket.

Correct?

Now do I need to put the rubber o-ring off my 9006 socket onto my 9005 bulb? And now this 9005 socket plug straight into my stock harness, correct?

 

You don't modify the socket (harness) and the bulb. Either use a 9005 harness from any auto store and wire it into your stock harness and then use an unmodified 9005 bulb, or modify the 9005 bulb to fit the stock 9006 harness. Either way works.

I do recommend doubling up the o-rings on the 9005 bulbs, because the 9005 bulb is slightly smaller in diameter than the 9006 (i.e. the 9006 won't fit into the high beam reflector because it's larger).