Here's my 2 cents on the matter. Take it for whatever you want. I have no idea why this guy all the sudden wants his kids but, that's his right. He probably doesn't really give a shit about them and the social worker doesn't give a shit either. I can't attest to her motives either which is why I just stick with her not giving a shit.
That said, they are going to do everything they can to win. If YOU truly care about your g/f and her kids, it's time to fucking suck it up and take one for the team. It's not about YOU winning like it is for them, you have something you care about on the line. This is serious shit. If it were me, not only would I take the stupid ass classes, I would quit drinking, quit dipping and quit wtf ever else I thought would look bad. Hell I would make dinner each night after work and we would all eat as a family. After February, life as usual. I would then look into every documented aspect of the case with an attorney and find any reason possible to sue the guy, the cps worker, her employer, the state and who the fuck ever else I could