stripped k1 street cranks? help needed!

my friend is trying to take off his cranks with the self extractor built in. but we think it stripped because the Allen key is spinning in both ways? how can we get the cranks off? :thinking:

a hammer?

Can you take a clear picture and post it for us? If your camera has a macro mode, be sure to use that to ensure it’s clearly focused.

Try to avoid destructive tools such as hammers, drills and torches, until you’ve exhausted other measures.

I’d guess that a bearing puller would do nicely. If you don’t have one lying around, you can probably borrow or rent one from the local auto parts store.

Mhmm, pictures.