How to change my old passcode in iCloud

Hi there Lost_boy688,

Are you asking how to change a device passcode or your Apple ID password? We ask because you can't change a device passcode using iCloud; it can only be changed from the device itself.

- Change Passcode: Enter a new six-digit passcode. Or tap Passcode Options to switch to a four-digit numeric code, a custom numeric code, or a custom alphanumeric code.

Have a look at the 'Change your passcode or passcode settings' section here for more information: Use a passcode with your iPhone, iPad, or iPod touch - Apple Support

If you want to change your Apple ID password that you use to sign into iCloud, you can do so from your device or by visiting this website: Recover Your Apple ID

Learn more about resetting your Apple ID password from this support article: If you forgot your Apple ID password - Apple Support

Take care.