How do you add a hole to a curved surface?

I’m working a part that is 80mm in OD, 20mm thick.
It has a center hole of 31mm ID.
It has 3 smaller holes of 6mm spaced at 120 °
I would like to drill a hold into the side of the circle connecting to one of the smaller holes at an angle of 60°.
Anyone know of a way to do this.
I’m using SketchUp 2015 Make version.
Thank you

Not quite sure about how you want to position the hole, but basically position a cylinder at the angle you want, then intersect the faces and remove the unwanted parts.