How To Un-Spoil Your Children?

So the summer has come to an end ... After you read that what was your immediate feeling? Sadness? Joy? Did you just take a huge sigh of relief? My answer would be: Anxious. I am anxious for the school year to begin and completely stressed out by all of the little things I need finished before I can calmly begin a new season. You see I have one tiny... little... itsy bitsy... big... daunting thing I need to  do... I need to un-spoil my insanely energetic boys! How do I do that? Seriously I am truly asking: How do you make your child less bratty? Well that just sounds mean... less demanding of things? No, that's not right either... how about More appreciative? That's better.
You see over the past three months I have raced through so many emotions I should have been diagnosed with something ... now that summer is over and I am beginning to clear my eyes and mark up my calendar I have taken a good long look at my boys and noticed that I have created MONSTERS! I guess I took the "whatever you want" approach to life this summer a little too far... Remember Wedding Crashers when Gloria is tantruming at her sisters wedding... I am Christopher Walken in that scene just waving my hands saying "whatever you want..."
Last week I tried the whole "if you don't do this, you want get that" type of bargaining. It worked once on each child and then I was turning onto a dead end road. The "Cold Turkey" method usually works well in my life when it comes to my addiction to sweets... Maybe that will work with the boys too? No candy, no jinky junk toys, no baked goods, no more crazy hupla! What do you think? How long will it take to have my nice even tempered children back again? Have you gone through this before? I need some help on this one.