Before your friend gives you their TM6, make sure they first log out of Cookidoo on their TM6 and also unlink their device from their Cookidoo account. When you receive the TM6 you will need to do a factory reset and can then log into your Cookidoo account on your TM6 using your credentials. Before you give the TM6 back to your friend, please make sure you have logged out of your Cookidoo account and unlinked the device (TM6) from your Cookidoo account.