how do I change the stylet tip on a one touch?

How do I change the stylet tip on a one touch home electrolysis? It doesn’t come out when I pull and there seems to be no way of dismanteling the probe. Also it has recently developed a problem where it won’t seem to shut off, yet the comfort dial is on 0, there is no moisture and no electric current at all… even when I turn it on. But it makes that noise… Can some one help please?

So i finally figured out how to change the stylet tip… but i am still having the problem where the unit won’t turn off the beeping sound unless i take out the battery…can anyone help?