Hey there! Having access to your Oculus account email is pretty crucial for anything account management related, and we'd love to help out with getting it changed so that you can change your PIN! There's actually a way you can change your PIN without having access to your account email, which was posted by one of our moderators in this thread.
If you still feel like you need your email changed so that you have access when you need it, please reach out to us in a private message and we'll be happy to help out more with changing it! To private message us, just click on our name to get to our profile, then click Send a Message.