Top Mount Nut Removal

Hi, I am struggling to get the top mounts off to remove the front shockers on the 2 I am breaking. Is it impact driver jobby only as I have snapped 2 allen keys holding the strut piston and cant shift em. If they were not new genuine renault items they would most definitely be staying on.

Thanks and sorry if this has been answered before but no joy on the search

yeah use an impact gun and cloth and grips to hold the strut from underneath

I use a deep offset 21mm ring spanner and an allen key thats held in place with a hollow metal bar. SO tight sometimes! Thought I had broken my thumb once undoing them.