Stuck steering rack snail nut

[Boboc.theo]

Hi,so i got a very loose steering,all my bushings are replaced,they dont move at all,i changed the bushing in my steering wheel still the same,hence that I saw on yt they tighten a nut on top of the steering rack,but its pretty stuck and cant seem to get it unstuck and in my country a steering rack is 600€ and cant afford it right now,any ideas how to get it unstuck?Btw my steering rack is ok i uninstalled and sent it to a service shop that ocuppy with them and they said it doesnt have any problems just need to adjust that nut.