Login to secure online portal https://my.iplum.com.
Accounts || Select Account || Profile & Permissions. You will see different options you can edit.
For login ID change, the system will send you a verification code which you will confirm here to complete the change.
Note: When you change login ID, it should not be already used at iPlum for another account.
To swap two iPlum login IDs, you will first change the first login ID to an email address, freeing up the first login ID phone number and then change the 2nd login ID to first login ID.