Changing all customer reward points at once

OpenCart Version: 2.0.1.1

Hello,

I am currently facing a small problem. I want to give all my customers who already signed up my website free 100 reward points. How can I give those 1000+ customers who pre-signed up at once 100 reward points instead of doing it 1-by-1 in the admin panel.

Is there any sql to do this?

Thanks!