How to 'mirror' null groups with manual pivots?

[Anonymous]

I have a bunch of null groups, and each null group has a manually placed pivot. These null groups are on the right hand side.

I was wondering how I would easily 'mirror' these null groups to the left hand side, and have the pivots of these null groups be mirrors of the original too, if that makes sense.

[Baboonian · Accepted solution]

group all, then scale X -1