In an 8 or 9 inch square pan, spread can of bean dip to completely cover the bottom of the pan. Next, mash the avocados, and add the lemon juice, and picante sauce to it; mix well. Spread the avocado mixture over the bean dip. Mix the sour cream and the taco seasoning mix together and spread over the avocado mixture. Sprinkle green onions, chopped tomatoes, cheddar cheese, and black olives over all. Refrigerate for at least 3 hours.