Hotswapping is a way to copy data to the HDD without having to unlock/relock it properly.
Data copied can include a working exploit and dashboard files, which would amount to a softmod.
Ready XboxHDM and the Art of Hotswapping for more info. It's in the pinned topics in this forum. That will teach you how to hotswap and get you going on XboxHDM which you'll need to use.
Also read up in the Ndure for PC installer thread. That's what you'll perhaps wind up doing once you understand XboxHDM.
Alternatively, you could just swap and copy an exploitable gamesave to the E: drive and run that save from it's coressponding game as a way to install one of Krayzie's packages.