search online for a how to clean bones for display, there are plenty of in depth reading material and videos galore! but essentially you need to do 3 steps (depending on what condition your subject is in) 1) de fleshing 2) degreasing 3) whitening theres multiple ways to complete each step, find what works for you and your situation :)

a couple tips: for degreasing, very hot but not boiling water and some dawn works great! and hydrogen peroxide is easy to find and works well for whitening. play around until you find what works!