To delete multiple repositories from the Git Integration for Jira app git repository/integration configuration:
Open the existing .tsv file that you want to use for this process. See the previous article for more information.
Under the delete column, enter "delete" for each repository that you want to remove.
Save this file and upload it via menu Git ➜ Manage repositories ➜ Bulk Change ➜ Import Configuration.
More related articles on Bulk change
Removing existing repositories via Bulk change (this page)