To change your password, kindly watch the following short video with the relative instructions.
More specifically:
Log in to your account
Select Settings and Profile
Navigate to the BUSINESS ACCOUNT SIGN-IN DETAILS and click Change next to the password
A pop up window will open on your screen.
Enter the existing password in the first field
Enter the new password in the second field
Confirm the new password in the third field.
Click the Change button
You will use the new password for all your accounts.