Unlinking 1 phone to a separate account

Good morning
I have 2 phones registered to my email address, I would like to unlink one to a separate account and email address. I rang customer services last night who talked me through it but to be honest was quite impatient with me and at the end of the process the phone was still linked to my account. I tried later but gives a message of Failed to delink msisdn...Please could you help? or is there a process that Lebara could separate the accounts?
Thank you

YvonneP try following the steps below. Let me know if you have any problems with the process.

Unlink your mobile number
Go to Account → Manage Your SIM
Select the option to unlink/remove your mobile number