If he's using SWM there has to be a power inserter somewhere in his system. The newer SWM-only receivers don't provide the DC power for the LNB's. The PI is a small device and could be right behind his receiver or anywhere along the cable run.
If you want to swap your receiver for his you will need to go into the setup menu and select Repeat Satellite setup. The receiver will ask "are you sure you want to do this?" and will require that you press the "dash" key "-" on your remote to proceed. At the next screen there are pulldowns for antenna type and switch type. Before you remove his receiver take a look at the settings for these two. The switch type will be SWM but it is important to note which antenna type is selected. When you put your receiver in place you need to use the same settings. After making the proper selection, check signal strengths and then your receiver should be ready to use.
Also, write down the antenna type setting on your receiver so that you can reset it to the proper setting when you take it back home. The switch type at your home will be Multiswitch.