How to remove rounded bleed nipples (courtesy of Tom306)?

[silverzx]

Basically cracked on and managed to change all the calipers, discs and pads over, went to bleed the system and realized the bleed nipples have been rounded off.

I've tried 6mm spanner that just spins and doesn't even grip. I've also tried mole grips which would also spin.

Any advice on this? Don't really want to have to take them all of again, is there any tool I could go buy tomorrow that would help?

I was thinking either an even bigger pair of mole grips or possibly a 4mm / 5mm deep socket that I try and hammer over it and then use to remove.

Obviously I've soaked them in WD40.

Suggestions please!!

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