Hex screw stuck advice

[gradeAfailure]

https://www.lasertools.co.uk/product/6844
We use stainless grub screws at work, which are forever rounding off, so I have a set of these.

 

[tintin40]

In the end i used Silver line Damaged screw remover 5 pc at £4.20 from Tool station. And is was easy. 10 seconds and the offending hex out. Replaced with a more robust item. Needn't had been so worried about such a job. Just hope i don't need to do again. I maybe booted out of the weight weenie club for replacing a light weight part for a heavier one
Thanks for all the help