How to Use Subversion with Codebeamer
Converting an Existing Subversion Repository to a Managed One
An unmanaged (external) repository can be converted to a managed one as described in
Creating Managed Repositories.
Associating Issues with Commits
If you want an SCM commit to appear on an issue page (under SCM Commits tab), just put the ID of the issue preceeded with a # to your commit message.
Codebeamer (if SCMLoop is enabled) will automatically associate that commit with the given issue. For more details see
Tracing Source Code Changes to Requirements, Task and Bugs.