Flip bone wight onto another bone?

Long story short i was quickly adding some bones on my person rig, and didn’t do it in symmetry mode. I painted some weight on this new bone. Now that i’ve made the corresponding mirroed bone for the other side, i’d like to copy/flip that weight onto the symmetric bone.

Ie, make one side of my rig/bone weights mirror the other side again. I swore there was a script for that, but i checked and couldn’t find anything.

Any tips?

EDIT

nevermind, found the script. :smiley: