Change iCloud name

I mean that when I try to send an e-mail using Mail, it says From: Husband Name <myname@icloud.com>. How do I fix this? It should be My Name <myname@icloud.com>. Same with everything on my computer. Anything that has been signed in with my iCloud account has his name. Everywhere I try to change it, nothing changes.

Thank you! Everything on my computer has reset and reflects my own name now. I did have to take a few more steps to get everything in order. So for others info: After changing your name in iCloud online, open up Mail and click the new message icon. When the new message pops up, select your new name from the "From" pull down menu then close it out. The next time you open it the old name will be gone. Then go to System Preferences, click on iCloud, click on Account Details, retype your name. Then everything will be set properly. Thanks again.