Multiple lightmaps

Hello all - I want to have 2 different lightmaps for my scene : one for the day and one for the night, and I want to be able to switch them a runtime. I know there was a way in Unity 4 with lightmapdata, but that was referring to lightmap near and far, and that is not in Unity 5 anymore. Anybody know how to manage multiple lightmaps in Unity 5 ? Thx !

you can save index and offset of each lightmaps and load them later.