Originally Posted by
xerman
Hello! I'm restoring an 20 years abandoned bike, but I found a type of headset I don't know how to open to clean and lubricate. I already cleaned the other parts of the bike and they were in awful state, just a bit of rotten grease.

What you need is a hook wrench. Pretty standard if you are in to plumbing. You can buy 'em cheap. Standard tool for any bottom bracket pre 1980.
https://www.google.co.nz/search?q=ho...HRlhl4DaeKHEM: