Log in with the Email & Password you set Mobile Rescue up with, To change Your PIN/Phone Unlock Code select settings and the last option is your phone unlock code it is displayed so you can get your old code or enter a new one and send.
In my case Mobile Rescue does not recognise my email address. I have only had 2 email addresses since I first used PC and mobile some 12 years ago. I cannot actually remember how I registered with Mobile Rescue in the first place. I do know I was given a 4 digit pin number which I made a note of and used at least once back in May/June to check the system,,probably less than 24 hours after I had registered. I never had cause to use it again until yesterday. And now I can't find the PIN. All my attempts to resolve this problem have failed. Can anybody help.