How Much Does Breast Explantation Cost?

I am now 63 and am beginning to realize that no other woman my age has such full and perky breasts as I do. I am beginning to feel self-conscious and expect that as I grow older, this will become more of a problem for me. I want to know if breast explantation is an option, what could be done to ensure my breasts would become much smaller and how much this would cost.