Changing the password for an SMB share user/pass entry

[spaceballl]

Hi there,
I set up an SMB share on my iTunes folder. I wanted to make a special account for my server to access the computer so I created a user called squeezebox-server by clicking the plus sign, then "new person." I'd like to change the password for that account, but there are no options on how to change it. Any help would be very appreciated! Thanks!