@paul-j-houghton I sort of grabbed the one I have attached to door frame and it came easily loose from the top leaving the mounting attached. Then I priced the bottom edge loose by a small flat screw driver. I had stupidly attached the button just above doorbell button so there's very little room to operate. The current of the battery measured just below 3V (cr3032). I have to try again with a fresh battery because this replacement didn't clip on and wasn't any better. I bought this button early last year.