If you have the OS Administrator password then from the CLI you can reset the CCMAdministrator password.
Please log into the command line and type the following:
run sql update applicationuser set
password='f3f84fcd7934cd48ef4fef0d9057c21d000ffe229fbd0a247ee491927aa30f02' where name='CCMAdministrator'
This sets the password for CCMAdministrator to ciscocisco
Then you can go into the GUI and change the password to what you would like it to be.
Log In To Cisco Unified Communications Operating System Administration:
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/cucos/6_0_1/cucos/iptpch2.html