Hi guys just realised i did the above and now stressing the new owner is going to fly around under my name. ( as the 4 plus comes with the screen on the remote so no need for phone)  Can i sign out or deregister this drone somehow?

The new User will use a different Account , dont worry about this , he must use his own Account to fly ...... not your Account

He ll not fly with your name .. or account

JetSam Posted at 1-1 01:48
The new User will use a different Account , dont worry about this , he must use his own Account to fly ...... not your Account

The new User will use a different Account , dont worry about this , he must use his own Account to fly ...... not your Account.

Think again.
The OP is talking about a + model.
The display is integrated with the controller and if the monitor already has an active account, anyone could pick it up an just fly with it without ever creating a new account for themselves.

JetSam Posted at 1-1 01:50
He ll not fly with your name .. or account

I never had to sign in as it was always signed in so as it’s a complete package he can continue to fly under my account

That shouldn't be a problem

Change your password.  It automatically forces the new password to be typed in before using on a relaunch or for a firmware update?  Just tell them to make a new account?