Process described on #releases channel here https://folio-project.slack.com/archives/CGPMHLX9B/p1590164280223800
Ask Oleksii Petrenko if you have questions.
Also related to the MARC_BIB to MARC change. Take Iris release vagrant box->upgrade to R2->upgrade to PR for reverting these changes (from Spitfire-team).
In the scope of this ticket were tested these modules:
Note: mod-source-record-manager and mod-source-record-storage don't have any scripts in these PRs.