I recently renewed my ssl cert for heroku hosted domain registered at godaddy. This post is a how to Guide for renewing/updating SSL Certificate issued by godaddy for heroku hosted domain without changing dns and keeping old ssl endpoint url. I hope it'll help somebody.
Step 1: Renew Godaddy certificate
Apply renewal credit at godaddy and use the previous certificate signing request(csr), selecting option of third party hosted domain and submit.
Step 2: Download Certificates Zip and Combine Certs
After the certificate has been issued by godaddy, download certs for 'Nginx' server. unzip the zipped file, cd into directory, and combine certificates.
cat 48bcdx31xxxx.crt sf_bundle-g2-g1.crt > combined.crt
Step 3: Update Certificate at Heroku SSL Endpoint
run certificate update command
heroku certs:update combined.crt server.key
Confirm the changes by typing app_name.
Step 4: Check Certificate Info
heroku certs:info --app=app_name
Step 5: Done!
Done! and after few seconds app is running on previous ssl endpoint url. So, No need to update dns.