Bella:
Hi Nathan,

Thanks for contacting Google Play Developer Support.
Now that we’ve verified your account, I’m happy to help you reset your upload key. The new upload key will be used to sign APKs that you upload to Play.

Here’s how to generate and register a new upload key:
Follow the instructions in the Android Studio Help Center to generate a new key. It must be different from any previous keys. Alternatively, you can use the following command line to generate a new key:
keytool -genkeypair -alias upload -keyalg RSA -keysize 2048 -validity 9125 -keystore keystore.jks
This key must be a 2048 bit RSA key and have 25-year validity.
Export the certificate for that key to PEM format:
keytool -export -rfc -alias upload -file upload_certificate.pem -keystore keystore.jks
Reply to this email and attach the upload_certificate.pem file.
I look forward to your response. Please let me know if you have any questions in the meantime.

Regards,
Bella
Google Play Developer Support

Me:
Hello Bella,

Sorry, I don't quite understand, so do I do them steps on a new project in android studio or... I don't have the original apps project files.

Bella:
Hi Developer,

Thanks for your reply.

The only thing I need is the .pem file, you may decide if you need to generate a new project or not.

I look forward to hearing from you.

Me:
Oh right, I’m sorry I misunderstood. I’m out for a day now and don’t she’s access to my computer so is it alright if this can wait until then or will I have to open up a new case?

Thanks,
Nathan

Bella:
Hi Nathan,
I just wanted to check in that if you still want to reset your upload certificate.

If yes, please reply with the .pem file and I’d be happy to help.

Me:
Yes sorry, I think I've got it, hope it works. (with attachment of the upload certificate)

Bella:
Hi Nathan,
Good news - I was able to register your new upload key. Make sure to update your keystores in the following locations:

Local machine
Locked on-site server (varying ACLs)
Cloud machine (varying ACLs)
Dedicated secrets management services
(git) repos
The new key will be usable from: 2018-07-19 02:16:52 UTC

Thanks for your patience during this process, and please let me know if you have any other questions.

Me:
Great! Thank you for your help.
So that would mean I can upload a dummy app using that key so I can unpublish it from the play store?

Bella:
Hi Nathan,

Thanks for your reply.

Yes, you will be able to signed it with your new APK now. And you will be able to upload it after 2018-07-20 07:34:38 UTC.

After your new version be processed by our system, please unpublish it and contact us after 24hours.

Please let me know if you have any other questions. I'd like to help.

Me:
Thank you so much for the help - sorry again.

Will do, do I contact you again or just start another ticket?

Bella:
Hi Nathan,

Thanks for your reply.

Since this ticket is for reseting your upload certificate. In order to track your issue much easier, I suggest you open a new ticket for your app deletion request.