I used three forums, BYO archive articles and google to find all the info on late addition extract brewing and full boils. The key factor in both is to adjust your hops additions. During those searches I found useful calculators to determine how much to reduce the hops. Hops utilization is factored by using volume and the specific gravity of the boil.
FWH or First Wort Hopping is another technique and it is easy. Add your flavor additions into the kettle as you are sparging. This will allow the flavor hops to steep while the sparging continues. Don't light the fire under the kettle until sparging is complete. The IBUs will still come out approximately the same but the bitterness will be smoother and more complex.:rockin: