To propose a modification to SAMOA, first create a JIRA issue describing the bug or enhancement at https://issues.apache.org/jira/browse/SAMOA (you need a separate JIRA account). Then, create a pull request with the proposed changes. Prepend the JIRA issue ID to the title of the pull request (e.g, SAMOA-XX: Fancy new feature).
Detailed info available in the contributing guide https://github.com/apache/incubator-samoa/blob/master/CONTRIBUTING.md
Assuming that you are developing your feature on a branch named after the JIRA ID (SAMOA-XX):
git filter-branch -f --msg-filter 'printf "SAMOA-XX: " && cat' SAMOA-XX master..HEAD