Oh I must have misunderstood your post then.. When saying "loosing that HD" I was thinking "kill it"...
Hotswapping is another way to softmod but thats pretty risky...
Other than using savegame exploits I can't really think of any to be honest. The thing is that you must be able to launch EvoX before you can get FTP access to the hdd..
Here's something about changing hdd.
You would be able to create a softmoded hd by using a temporary chip (preferably solderless), put it in your xbox, change hdd, power on, use SlaYers and install a chip requering installation and after that get krayzies, put it in the dir it is supposed to be, add that dir into the EvoX menu so that you can start that install. Start that install, complete it, power off, remove chip, power in with softmod install...
You could also do the same thing using another xbox but that would require swapping EEPROMs and I am not to comfortable with such things...
If you are not still happy with my answers (my knowledge in this matter is somewhat limited) go check out
www.xbox-scene.com in the forums and stuff, they'll provide better answers and knows just about everything...