Basically, you don’t. If that was possible, then anyone could steal a card and bypass it and gain access to anyone’s account and take everything. You are just going to have to contact the bank and either change it over the phone or go into the branch and have it changed there. When you do, note how detailed they will be in ensuring that you “are” the person you say you are. One mistake and you will not be able to change the PIN. Good luck.