Rinse each avocado under running water, and make sure that you wash it thoroughly. It doesn't matter whether you grew the avocado yourself or found it laying on the sidewalk, it's important that you rinse any chemicals and bacteria from your produce before you eat it. Dry the avocados with a clean towel afterwards to remove any persistent debris. Use a sharp knife to cut around the avocado lengthwise. Carefully place it on a cutting board, and start slicing at the top of the avocado. Rotate the avocado and knife so you cut around the entire avocado and meet up with the initial slit. Then hold the two halves of the avocado and twist them in opposite directions to open the fruit. Use a sharp, sturdy knife, and place the pit-containing half of the avocado on a cutting board. Thwack the knife solidly into the avocado pit (1/8-1/4 inch deep) so that it won't easily budge. Then, hold the avocado firmly and twist the knife (and attached pit) until the pit dislodges from the fruit. Tap or slide the pit off of the knife into a garbage can or compost bin.  Exercise great caution when using a knife. If you don't want to use a knife, you can remove the put with a spoon. If you use a spoon, try to wedge your tool beneath the seed and separate it from the surrounding meat so that you can scoop out the pit. Now that you have two avocado halves, cut the avocado halves in half again, to make 4 wedges. Then pull the dark outer skin away from the green flesh of the fruit. Peel the fruit by sliding your thumb in between the skin and meat of the fruit, and peel the skin back away from the meat.  If you slice the avocados open and scoop out the meat using a spoon, you don't need to peel the avocado. However, many people favor peeling off the skin of the avocado because it ensures you retain the dark green, high-nutrient layer of avocado meat closest to the outer skin. Consider cutting away the tough area where the stem meets the avocado. If you don't remove it now, you might find it amid your avocado butter later! You can hand-mash the fruit in a bowl, or you can grind it in a food processor. Either way, mash the avocado until there are no large chunks remaining.   If you are hand-mashing the avocado, use a fork or a mortar and pestle. Chop the avocado into chunks first to make it easier to mash. You want the mixture to be smooth like guacamole. If you are using a blender or food processor, put the avocado chunks into the machine, add all of the ingredients, and close the lid. Process until there are no large remaining chunks. This method is best if you're making a large quantity of avocado butter – it will be much easier than hand-mashing.
Wash the fruit before preparing it. Cut the avocado. Pit the avocado. Peel your avocados. Mix and mash the avocado with the other ingredients.