Anyone use the Transfer Cable?

Did any one use the transfer cable? I need to mover to a biger hardrive and put my new hardrive to a new xbox. I calld xbox they sent me the stuff i need. But i never used it and i read the manual and it scares me lol. I dont want to lose any of my game saves the background and ícones i can get back later. But did anyone have any problems with using the transfer cable?