Hi Shirali
If you have signed in the bolt app using email id and password, then you can use the forgot password option to reset the password.
If you are still facing issue signing in and you want to link the device to another email id then please write an email from your email id cygnusbolt2@gmail.com to support@boltiot.com requesting to link the device with a new email id. Please mention the device id and the email id to which the device has to be linked.
Do try this and let us know.