Give it time and handle it calmly and securely. Sit down with it on your lap or hold it against your body giving it good contact. You want it to feel secure. After that it's just time. It will probably relax around you but there is really no guarantee. My Ball still balls 9 times out of 10 when first taken out. She's been with me over 10 years but it's hardwired in. After I take her out she opens up in a few minutes and then calmly hangs around my neck.
My youngest King has finally started to learn I'm not a bad guy and stopped musking me for the most part. He was very scared but with regular handling he's come a long way.