I'm trying to remove the transmission casing on my belt drive scooter. All of the bolts have tiny 8mm heads, and are very cheap and soft - cheap Chinese manufacture - and one was already slightly rounded, from assembly as a new bike.
I have now sprayed Q10 penetrating oil, and waited a few minutes before tapping lightly with a hammer, on the front and sides of the bolt head. What is really worrying is that when I tap the side of the bolt head, it moves as much as 0.7mm, in any direction. The head is too close to a casing piece to get any good grip with a vice grip.
What can I do here? There is no room to cut a groove with a hacksaw, but maybe if I get a thin enough grinding disk on an angle grinder I can cut a groove, or maybe grind the head flat enough for a vice grip to hold.
What can I do?