Please note that removing a repository will only remove the Icinga for Windows configuration and not the files on the disk. You have to do this step manually.
In case a repository is disabled, you can enable it with
Enable-IcingaRepository -Name 'Icinga Stable Internal Web';
You can also disable enabled repositories with
Disable-IcingaRepository -Name 'Icinga Stable Internal Web';
Please note that disabled Icinga repositories will be fully ignored during installation/update tasks and no files from these will be fetched.
If you no longer require a certain repository, you can remove it with
Remove-IcingaRepository -Name 'Icinga Stable Internal Web';
Note: This will only remove the repository from the configuration. All possible available files for sync runs or anything related will remain on the disk until you remove them manually.