Assuming it’s a standard cable operated handbrake, you’ll be needing a wind back tool, as the world and his dog said above.
I had one very similar to the one you linked to. Lost some of the parts to it, so I got a 15 quid ebay universal kit which has a dozen or so different adaptors for different pitches of wind back pin, as well as LH and RH threaded windback tools. I’d go for the ebay kit every time – the wind back tools are overbuilt for what they do and a big kit will have a decent chance of fitting your next car.
And I ended up replacing both rear calipers, and the handbrake cables as they were seized into the calipers.
If there’s a good way of removing hand brake cables, I’d love to hear it! Heat melts the outers, belting them tends to just mash them about, clamping them in mole grips crushes them…