Print both kebdama parts and two halfballs. Glue the parts together. Make sure the spike fits into the ball. You may have to clean the inside of the ball to make it fit. Glue the parts together.

I drilled a hole for the string. I guess I could have printed the hole, but it would never have worked anyway. Drilling works :)

Mine is printed with a 0.5mm nozzle, 0.3mm layer height and 4 outlines. With these settings, it may have some holes, so I guess you should print it with 0.1 or 0.2mm layer height.

Source is 3ds max, so here's just STLs