It's ok to ask idiotic questions, it's not ok to help someone out by confusing them, so since you're the original poster, no one would have laughed, if you had expressed a doubt about the first reply. Better safe than sorry.
"6+2pin is the same thing as an 8 pin, just already broken off professionally right?"
Right, more like a 6 Pin connector + a 2 Pin Connector.
You could go and cut the two pins off using a knife or heated knife. BUT.
What if you need the 8 Pin socket tomorrow?
What if you need to get a new Mobo that might need the 8 Pins?
If it doesn't fit directly onto the mobo, then the safest way to go would be to buy just another 6+2 pin extension cable.