Users can use the Interchange administration interface (UI) for reconfiguring their catalog. Alternatively, you can configure sudo to allow users running interchange from the commandline:

sudo -u interchange /usr/sbin/interchange --reconfig=linuxia

Add the following line to your sudoers file with visudo to give permission to do so:

racke LOCAL = (interchange) NOPASSWD: /usr/sbin/interchange --reconfig=linuxia