Seagates are pretty standard. If the files are very important and all that you're better going to a pro but it's about as complex as changing a tire, replacing a broken light switch, etc. bearing in mind lots of people manage to drop their car or electrocute themselves. Plenty of Youtube video demonstrations, don't know the normal pro cost but in geek coinage the going rate if you showed up at a CompSci Dept with the new enclosure would be like a six-pack of mountain dew and sitting around for ten minutes listening to blather about how easy it is and how much they hate/love X manufacturer. Even if you screw it up you won't destroy the files - unless you drop a screw into thing and start thinking about how easy it would be to get out with a magnet, so I'd suggest do-it-yourself for the experience, it's five minutes and a screwdriver.