I have 5,000iu vials that I add 5ml bac water to mix up. To get 500 units in a 1ml syringe, I would fill it half way to the 5 on the syringe. You have a 10,000iu bottle (double mine) so I assume that you would take half the volume, 2.5 in the syringe.
The official protocol I’m prescribed is 330 units 3x a week. I don’t strictly follow it though and it works out fine. I do closer to 250 units on average and skip shots here and there. I’m not planning to have anymore kids, just taking it because I have a lot on hand, and it makes me feel good and shoot bigger loads.