I'm working on my On-One Inbred and when loosening the top cap the "star nut" (in this case it is actually just a disc) is rotating inside the top tube. I take it that this is not the way it is meant to function. So i assume that i'll be replacing it very soon. My question is this: how can i keep it from rotating to get it out? I thought about tapping the whole thing up and out, since it is obviously loose, but in reading Sheldon it seems as if this might damage the head tube. Any suggestions?

Also, are there any reasonably reliable "homebrew" methods for installing a new star nut? I'd prefer not to buy a tool i will in all likelihood use only once, but since it's relatively cheap i suppose i can if there's not a good free/cheap method. This is the second new-to-me technology that has failed miserably today. First the self-extracting crank bolt completely stripped the extraction threads, and now the damn star nut won't do its job. Not to sound too retro-grouchy but at the moment i am really not seeing the value of these improvements.