Smooth gMail password change

Hi, my wife and I have recently become concerned about the security of our primary IMAP email accounts. We both use gmail as our primary accounts and my wife has 3 more secondary addresses linked to her primary account.
We both use Apple Mail as an email client on ourMac Books, iPhones and on my wife's iPad.
We have both had our gMail accounts for over 8 years so you can imagine we have fairly simple passwords. We have never been tempted to change them before but the recent focus on online security, identity theft and hacking has us considering a change.
We have committed all of the security no-no's over time sharing the same password for different sites etc. It was never really an issue till recent times.
So I have looked online for a complete set of instructions on how to do this, avoiding all of the problems mentioned by so many. Will changing the primary account password effect secondary gMail accounts?
Should I delete the password for the account from KeyChain first or delete the account completely on my MacBook and create a new one with the new password. Should I do this also on my iPhone or just change the password in Settings >Mail, Contacts, iCal?
You can see I have a lot of questions, all prompted by reading the online tales of woe from others trying to do the same thing. It seems there are all sorts of problems to avoid but no definitive set of step by step instructions for multiple iDevices and apps.
I would like to; a. Change my password at Google settings > change password.
b. Change password in Mail setting on my iPhone and iPad and have everything work as before, but the articles I have read give me no faith that it will be that easy (is it ever?).
If anyone can help with this we would both be very grateful.
Rod

Hey Rob and welcome from another Antipodean

The easiest thing to do to is change your Primary password. LINK. I gave you this link because it for older versions too, but if not use this with links as long as you are signed into Google on your Browser already.
Then you will have to go and change the passwords on all your iDevices and MacMail individually.

You can on your Mac goto the Apple top left>System Preferences>Mail,Contacts,Calendars and then click on the Gmail Account in the left column, then Details and change the Password there for the Account on your Mac only.
I use the Gmail App on my iPhone, but to change the Password on the iPhone in the Mail App, goto Settings>Mail,Contact,Calendar>Accounts. Click on the Gmail Account then scroll down and change the password there. It will be Dotted out in that window just like in the Mac Preferences one.

There is no need to delete the PW from keychain as that will just update the current account once it is changed, and to check it out, open Keychain Access, and it will show you at the bottom of the window of every time you have changed the PW and from what it was.

Can i suggest a great Password Manager for both you and your Wife that will keep track of ALL your Passwords for all email accounts, online accounts, credit cards, App/Software Registration Keys, and ANYTHING else that you think is valuable that you use online or in your personal life.
One such Manager (and ill have every member here back me up on this) is 1 Password ~ For Mac, iPhone & iPad, which you can put on your Mac, iPhone and iPad. I have ALL 3 version as they sync over iCloud or Dropbox and i feel as safe as Fort Know. This manager also Generates Passwords for websites when you join one and saves it automatically and with a Safari Extension its only a 2 key press for me.When setting it up, it will prompt you to install the extension so no effort on your part
How much is your security worth ?? 1Password will make you feel safe

I suggest as well that if your changing your Primary Gmail Account Passwords, and you feel you need to on the Other 3 accounts, then do so as well, Changing the Primary won't change the others, as they are separate accounts, UNLESS you used the same Password . . .

Hope that helps and make sense but post back if you need more info

Cheers

If you are going to change your Gmail password, you might consider enabling 2-step verification, as well. It adds another layer of security, and is quite easy to set up.

And I also recommend you consider using 1Password. It's a great app.