With the Slingbox product, the initial setup needs to be completed at the Slingbox location. This is because in order for the Slingbox to stream your TV service over the internet, you first need to configure it to your local network. Those steps cannot be completed from a remote location. However, once you have completely set up the unit, there are certain parts of the setup process that you can amend and update from a remote location (for example: actions surrounding updating TV service and reconfiguring to a different virtual remote control skin).
I assure you that the setup process is actually quite simple, but it would definitely need to be initially performed at the location of the Slingbox. If you anticipate your parents having difficulty with the steps, I would absolutely invite them to contact our technical support department. We would be happy to help them out. Additionally, check out these Slingbox quick start guides. They will get you started off on the right foot.
Hope this information was useful.