This can be accomplished with the current Adaptive Performance package using the below sample code.
var apm = GameObject.Find("AdaptivePerformanceManager");
var managerSettings = AdaptivePerformanceGeneralSettings.Instance.Manager;
if (!managerSettings.isInitializationComplete)
return;
managerSettings.DeinitializeLoader();
apm.SetActive(false);
Debug.Log(managerSettings.isInitializationComplete); //this should be false
Debug.Log("AP Loader: " + managerSettings.activeLoader); //this should be null