If you want to change your password to something more secure, you can do so by clicking Settings in Profile under your profile avatar.
Click Change password and enter a new one.
If you've forgotten your password, simply click on the 'Forgot password' option to recover it.
Provide the email address associated with your account and press send.
For both "Change password" and "Forgot password", you will receive a verification code via email.
Enter the code and new password and click "Submit".