[H] Clear XBOX 360 slim

[Winterlight]

I have a XBOX 360 purchased from MS In Nov 2012. It has always been 
stock. It has no hard drive and I do not recall ever using the DVD 
player. I only used it as a  linked TV box for windows 7 and 8 media 
center. I have a HDhomrun that  works with a cable card. That is all 
I used it for .. no games .. no DVD playing. MS makes you create a 
profile on start up and when I plugged it in today it updated itself 
and showed that profile name.

It has sat in storage for the last three years and I want to give it 
to somebody but I want to set it back to factory settings. I have 
followed various you tube online instructions and there are a bunch 
of steps. But I don't have a hard drive to format. I have cleared the 
cache, removed my profile, removed family settings. And yet when I 
turn it on it starts looking for media center. There must be an easy 
way to clear this thing off and reset it back to factory settings so 
it starts up like a new device?