Campag Zonda rear hub stuck

chatlow Posts: 845
hi all, Ive spend a solid hour trying to loosen the hub and remove the end cap and from my zonda rear hub.

With the cassette freehub body removed, the instructions say to use 2x 5mm allen keys either end and turn anti clockwise and the non drive side end cap will unscrew so you can remove that and then the preload collar.

This end cap is not budging, so just wondering if anyone has any tips before i look for a LBS tomorrow