Originally Posted by sasander
I tried putting a screwdriver into the notch and whacking it with a hammer, but it was phillips and kept slipping out. Also felt like this could damage it.
Why don't you just go to your LBS have them tighten it for you? While you're there, get a lockring tool (and a chainwhip) and have them show you how to use them. There's a point at which DIY isn't an option for the given cyclist (if posts to this forum are any indicator, the track/fixie community is waaaaaay too much into the DIY/get it used from someone you know outside the LBS thing- but I can't say for sure), and if you're trying to tighten a lockring with a phillips screwdriver and a hammer, perhaps you don't need to be wrenching on your bike just yet. No insult intended, whatsoever, but my suggestion is better than having you strip your hub trying to fix something you don't have the tools to fix. A bike is not a toy. Especially a brakeless track. It can very easily get you killed if it isn't working properly.