My assumption is that you are referring to the Windows 10 PIN that Firefox Lockwise asks for in order to view your passwords. In that case, refer to the [https://answers.microsoft.com/en-us/windows/forum/windows_10-hello/how-to-change-pin-personal-identification-number/57f6ad69-fcc2-4ea4-9af4-cd0229c37849 How to change PIN (Personal Identification Number)?] page in Microsoft support. If you are talking about the Master Password in Firefox, you can change that from the Firefox settings page under the '''Privacy & Security''' section. If you scroll down to '''Logins & Passwords''' there is a '''Change Master Password...''' button there. If you have a Master Password set on Firefox, but don't remember what it is, you can reset it. See [[Reset your Master Password if you've forgotten it]]. However, '''that will erase all saved logins and passwords in Firefox'''. Hope this helps.