Uncatalog a DB Alias

Hi, I have install DB2 dataserver client on Linux server to connect to DB2 on Z/os and the connection works after catalogging TCP/IP node and the database. But now I have to change the database alias name. Can I issue the catalog database command with different alias name or first Do I need to uncatalog ? The command issued for catalog the MF database is as below:
catalog database DB1 as FINDB at node db2node
authentication server