Just adding that you almost definitely ripped off the negative pad, looking at this [link|https://upload.wikimedia.org/wikipedia/commons/d/df/Xbox-Motherboard-Rev1.jpg|high-res image] of a motherboard, you can see similar capacitors on top of that same footprint. Schematics for most revisions of the Xbox motherboard can be found online, and you could use that to confirm that this capacitor's negative pin is routed to ground. If so, then it's a pretty easy repair and you could resolder the negative end to an adjacent component electrically connected to ground.