drain plug on rad

[ZJB-400]

I'm trying to drain my rad but the drain plug is making me look real stupid. 2002 sonoma 4.3
I've attached a picture of the drain plug, can someone please help me on this.
Nothing is easy anymore.

I have discovered how to open the drain plug. 1/4" drive fits perfectly. One small probem. I think my rad is so plugged up because nothing is draining. My drive way is paved and I really don't want to make a huge mess of my driveway and my engine, is it possible for me to just add the cleaner, run it for a while and then try to flush? Obviously I will flush agian, probably more than once.