Iterating over all scenes before compilation


I need to iterate over all my game scenes with script and make some changes. I need this to be done before game compilation.

I’ve tried to google preprocess scripting in Unity. Did I understand correctly that I need to use something like BuildPipeline? Are there any simple examples to understand how does it work?

I would really appreciate any help.
Thanks in advance.

Well, finally I managed it myself. If someone will face same problem, here is my script:

class MyBuilder : Editor {

    private static string[] FillLevels ()
        return (from scene in EditorBuildSettings.scenes where scene.enabled select scene.path).ToArray ();

    [MenuItem ("MyTool/BuildGame")]
    public static void  buildGame()
        string[] levels = FillLevels ();
        foreach (string level in levels) {
            EditorApplication.OpenScene (level);
            object[] allObjects = Resources.FindObjectsOfTypeAll (typeof(UnityEngine.GameObject));
            foreach (object thisObject in allObjects) {
               /* my gameObjects changing before compilation */
            EditorApplication.SaveScene ();
        BuildPipeline.BuildPlayer (levels, Path.GetFullPath (Application.dataPath + "/../game.exe"), BuildTarget.StandaloneWindows, BuildOptions.None);