You can do it from:
 
Personal Space
When the password is valid, you can change it from account_circle Personal space > General > Password
 
Access to EACAT

When your password has expired or you don't remember it, you can change it from the link Have you forgotten or has your password expired?

Find related information at:

AE - How can you change your password?
AE - What can you do if you have forgotten your password?

AE - AOC Password Security Policy