I CANNOT get the front strut nut off

[naossoan]

I'm trying to install my TEIN springs. I got the back done easy peezy. I've got everything off the front necessary to access the front strut bolts with the alan key inside and 17mm nut.

I CANNOT use a box wrench to turn it, it just starts to stip the upper part of the bolt. I CANNOT use a ratchet with a socket to loosten it because I need the alan key to hold the centre from moving.

How the bloody hell do I get these nuts off? The spring install guide makes it sound easy peezy but that just is NOT happening.

Does anyone know if a socket with a hexagonal outside (instead of completely round) exists? You know then I could use the socket and use a large like 19 or 21mm box wrench to turn the socket...

OR anyone have any other teniques?

Thanks