Now, this won't work very well if you are looking to use slices of avocado. It is much better for using avocado in recipes or dips. According to an article at Huffington Post http://goo.gl/KWfvTp you can either half the avocados, remove the skin and then freeze or mash them, add a little lemon juice and freeze (we like to put them in quart sized bags). We have never tried the halving methods but have tried the mash with some success!
Make sure to check out the Huffington Post link for recipe ideas for those avocados!