I use a breaker bar, short extension, 1/2 to 3/8 adapter, and a 8MM hex bit socket. Torque when replacing them is 38 Newton Meters, which is 28 foot pounds.
When in TDC and the nuts adjusted all the way down, the first rocker set just came right out. The back set popped out when I moved the engine a little.
I'd also recommend getting a 14mm ratcheting box wrench that pivots (or that is angled) so that you can get those adjustment nuts up and down the valve stems quicker.
As a matter of fact, here's a photo...
