As Cees says, and make sure you have a towel or something soft on the floor, so if they bounce off they don't hit concrete or gravel
i have more problems getting the chrome rings on, i think the secret is to push them on a little bit at a time working around the wheel, i tried pushing one side in and then wallapping the other side with the palm of my hand, they bounce off like a missile and i just get a sore hand