There is no mass change option for passwords in whm/cpanel, however, you can make a script to automate this using the password change function in /scripts if you need to.
PlatinumServerManagement (also known as PSM)
The OLDEST and LARGEST and MOST TRUSTED server management provider in the USA, with 15+ employees and growing! Providing quality support for OVER 18 years! Currently supporting over 3,000+ servers monthly! www.PlatinumServerManagement.com Proud member of the NJ BBB & Chamber of Commerce & Authorized cPanel Partner.
either you will have to do it manually from list accounts option after you login as root..to the whm, changing password individualy too will be faster.. I hope you need different passwords for different accounts.. It should be possible by writing a shell script to do this from terminal, basically keep in mind this that when you are changing the password for a user from whm , the cpanel accounts password , main ftp password , mysql password are getting updated.. So if you write a shell script.. For randomly assigning a password to the cpanel accounts. And saving the password to a file..test it on dummy accounts and then only proceed.. Alan