Microstation CE Update 16 C# : How to set level name and line style name for existing line element?

Need to set the level name and line style name of the existing line element.

LevelHandle levelHandle = Session.Instance.GetActiveDgnModel().GetLevelCache().GetLevelByName("Plastic 20");
            LevelId levelid = levelHandle.LevelId;

            ElementPropertiesSetter propertiesSetter = new ElementPropertiesSetter();
            propertiesSetter.SetLevel(levelid);

This is how we can get the level id by level name of the existing level and set it to the existing line element. However I want to apply new level name to the existing line element?

Should I set Bentley.MstnPlatformNET.Settings.Level = "Steel 21", but then how to update this with existing line element

Similarly for Bentley.MstnPlatformNET.Settings.LineStyleName, how to update this with existing line element

Regards,

Varsha