easy. eliminate attacks of opportunity rules and any combat move whose result may create one for either side of the combat.
eliminate flanking rules and anything to do with giving any bonuses to anyone for flanking, including eliminating giving thieves the ability to flank and backstab in battle.
eliminate every combat move other than swinging a weapon at someone. this means eliminating trip, grapple, and all the rest of those listed in the combat section.
lastly, give one attack per round to everyone except fighters who get 2 at 10th level.
that ought to do it. we have implemented all of those rules in our game except the one giving everyone one attack per round, and our combats are faster than most i think.
