The final step in how to organize your passwords is to systematically go about actually making the changes. The order you do it in could make a difference in how easy it is to do. You want to be careful not to lock yourself out of one site while resetting something else.
To get started making the changes, first, check the backup security info (phone number and back up email) in any account BEFORE starting to reset. For example, go into the Google Settings and see what backup phone number and email are listed. If they are incorrect; if you no longer have access to that phone number or email; then change that information first before changing the password.
The phone listed for security settings should be a cell phone if at all possible. The easiest way to confirm an account is to receive a text with a code and enter that code into the site. If the phone number listed is a land line, then usually an automated phone call is an option, but someone must answer and write down the code. The time limit for the codes is quite short.
Order of Attack
An active email account is the most important password, probably followed by an Apple ID for iPhone users. Those accounts will be used to verify other accounts as changes are made. Make sure to have access to those before beginning.
Next, attempt a reset for any account with no current password. Follow each one through to the end before attempting the next one. The worst scenario is to lock yourself out of one account which is then needed to confirm the changes to another account. There is minimal risk if each change is stepped through one at a time.
Depending on the situation, it might also be useful to create an email address that is only used for resetting passwords. Then go into each account and set this as the backup address. This is sometimes useful when there is only a single email address, because it at least gives a backup address for the main email.
This is a process that can spread out over many days easily. Keep track in a careful and stepwise manner. Good luck and please give us a call if there are any problems.