This was a great article in the Huffington post about how to tell your spouse you want a divorce. The article states that you need really educate yourself, especially what will likely happen to you financially going forward.
The main points are that you need tread lightly and don’t blindside your husband or wife. So in other words, saying you want a divorce out of the blue is probably not a good idea. Maybe try counseling and express your concerns for awhile before just getting out.