From what I remember from my dim and distant 'minibus' years.
Press and hold the priority button on the sidestick.
LOUDLY announce 'I have control' as the system calls 'Priority right/left'.
Execute the go-around and then, when safe, explain to the now 'unloaded' PF why you took control.
We all get tunnel vision at some point and start to lose senses whilst we grapple with a deteriorating situation of our own devising. I brief my colleagues on my sectors that I am distinctly average and not clever enough to be clever therefore if I am doing something stupid intervene!!!
At the company I work for co-pilot intervention is often taught as a module in the sim and very welcome it is too.