How to request for Android Upload Key changing to google support.

Step 1: Go to Google Play Console and click on the app on which you want to change the Upload key.

Step 2: Click on Setup, App Integrity  and Go to App signing Section. then Scroll down to Upload Key Certificate Section.

Step 3: Click on contact our support team Under Upload key certificate section, where you will see a form.

Step 4: Now you'll get a form to fill up.

1. select your location.
2. Give your Developer name [copy your developer name from google play console developer page.]
   

# This screenshot can help you to get your Developer name, Developer account ID and Android Package name.

Step 5

1. Give your Developer Account ID [Copy your developer Account ID from Account Details page from Google Play Console]
2. Give your Existing app package name.
3. Check on Yes, Google Play manages my upload key and specify the reasons as indicated on the screenshots.
   

Step 6: 

• Download  upload_certificate.pem file from here.
• Click on + Choose files and select upload_certificate.pem file.
• Click on Submit to submit the form to Google.

After the submission of this form you'll receive a confirmation email. After the confirmation it may take few days time for the completion of Upload Key changing process. Then you can submit your new app from a new Android Package Name as an update to your existing app.