Username change problem~

Hi All,

I want to change the username from Andy Yap Sing Hoe/CCA to Yap Sing Hoe/CCA, is there a correct way to edit this username because what i did is directly edit person using "edit person". And when I done change it, and test send email the i received from  Andy Yap Sing Hoe/CCA  not from Yap Sing Hoe/CCA and ACL to yapsh.nsf is set to Yap Sing Hoe/CCA not Andy  Yap Sing Hoe/CCA .

How can i correct this problem?. :)

Thanks in advance~