In order for you to change the password of CometChat?
Step 1:
Login to CometChat admin panel.
Step 2:
From Left Menu Click on "Settings->General"
Step 3:
search for "Admin Panel Login Details".
Step 4:
Change Username & Password as per your requirement.
Step 6:
Click on "Update" Button.
Step 7:
"Clear Cache" from left menu
Step 8:
"Clear Browser Cache"