I need help replacing a dead hard drive in my 1.2 model xbox classic.

I recently acquired an original xbox 1.2 model from my local game store. He sold it to me as broken for $12 because it was really loud. When I booted it up it gave me an error 07 message. After some research I found either my IDE cable was bad, wasn't plugged in all the way, or I had a dead hard drive. I unplugged and replugged the ide cable and then bought a new known working one on ebay and tried it. Still no dice. So now I'm thinking I need to replace the whole hard drive. But I'm still really new to the console repair world and I have no idea where to even begin! I know I need to softmod my system for any new hard drive to work, but how is that possible if I can't even get to the menu after the error screen? I've heard of a modchip called the Aladdin x2 or something, but how does that all work? If anyone out there could provide some insight I'd be grateful for it. I also dont understand alot of computer words so bear with me if I sound confused. I do have a laptop for transferring files if that's something I need to do. Thank you in advance!

Edit- I read somewhere that if I unplug the IDE cable from the hard drive I should get an error 08. If it's still error 7 then it could be the disc drive. I took out my disc drive from my personal working xbox and it still didn't work in the broken one with the same error 7 code so that wasn't it either. Also my new IDE cable worked fine in my personal xbox as well so it wasn't a faulty cable.