Option 1: If the engine has an electric starter as well as the rewind starter, just remove the rewind starter and see if the squeal goes away. If it does go away, follow Option 2.
Option 2: If it doesn't have an electric starter, you need to remove, dismantle, clean and lubricate the pull start. If you post the Model, Type and Code information, I should be able to post instructions for doing this.
Do not ignore the problem. If it is the starter, very soon the squealing shaft and bearing will seize, the starter will spit out its cord, and it will probably be ruined.
