New to seafoam

Hope this is posted in the right section. I have a 98 150 faststrike and have had absolutely no problems for 2 years now. I want to keep my engine running good and have read several articles about seafoam. I have never done this and have no clue how to do it or whereto buy it. Could someone treat me like a dumb blond and tell me what to do to treat my engine. I run the standard evinrude/johnson oil you buy at wal mart.

You add it to your fuel system it decarbs the motor via the fuel system. You can get it at any auto parts store. Wal-Mart may have it in their auto section. Mix it according to the directions on the can.