hard drive swap

There is no legit way to do so. Anything that could be done would violate the terms of service and cannot be discussed here.

Thanks, it's only going upstairs to his bedroom and I have all of the games on disc.

Should that solve it all?

You can but you'd still run into a couple of issues.

First would be that any installed games (from disc) would need to be reinstalled. For some reason Microsoft made it that games installed from disc will only run from the hard drive if it is in the console it was installed on.

You would need to do a license transfer. The digital content would still work if you were connected to Live but if you lost your internet connection for some reason then you wouldn't be able to access any of it.

There will be no change you would be able to play on your save if you have your hard drive in but your friend unless if he has it saved on his xbox then he wouldn't be able to play on his save unless you swap hard drives again. And make sure the console
is powered off when you do switch and you shouldn't lose anything.

as long as you remove all Hard Drives and USB Memory sticks there will be no changes to any game you play because all saves will either not be able to be saved anywhere, or will be loaded from the new Hard Drive and saved to the new Hard Drive.