How to adjust oil in recipe when adding peanut butter
Natural Peanut butter is about 50% fat, butter is about 80% fat. If you want to maintain the original amount of fat in the recipe, you would decrease the butter by 60% of the amount of peanut butter you used. So if you used 1/3 cup of Peanut butter, subtract about 1/5 cup (a little less than a 1/4 cup) of butter from your recipe. Don't adjust the eggs. 

Hope this helps! I had to use too much math to get to the answer.