Before you do any processing of such changes, you need to verify it is a valid email .  create a ticket using the new email and send a request to confirm.

now if they aren't already in the records, you can go to admin - > manage users 

type in their old email address, 

Fill in the user manager field to pull up the account.  Then click quick-edit to pull up the info.

then select edit and it's where you can change

change the password and select change.

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If it is a shared access for lot, get the lot numbers

1. go to istall management account

2. go to site management access

3. put in lot listed in category

4. Select filter. 

This will give a list of whom has email access

you can add users email by clicking the add button

you can remove users by pressing the delete button to the right of the email listed.

you can change the email by clicking edit, provided it isn't already in use.

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<need walkthrough if email is already in the system>

If you get the following error message

 "That email is in use by another user."

That means that the account is already connected to another account.

Your mostly going to have to delete the accounts and rebuild <will fill in details later>.