The old lucene-solr.git repository is read-only and any existing Pull Request will need to be re-created in the new lucene.git or solr.git repository.
Please consider using this https://github.com/apache/lucene-solr/blob/master/PRs.md instructions instead of the non-tested ones below (which require you to setup a fork of the new repo first.
Alternative approaches (NOTE TESTED)
Prerequsites
You need to know your fork's repository and branch name
...