change mobile in iCloud Keychain in Mac

Old phone number for iCloud Keychain? How do I change it?

Open system preferences and click on iCloud , click on account details and sign in with your Apple ID and password click on continue .

A window appears , select contact and click on plus sign .

A third pop up window will appear select the small circle of phone number , in the phone number field tap it once and type the new mobile number and click on next , a verification code will be sent to this number and follow the upcoming steps , the new number is added in iCloud Keychain .

Later you can delete the previous mobile number by clicking on minus sign .