I'm a bit confused after reading forums as to what drives I can put in my Tivo Premiere-746 and what steps to get there. Several threads seem to indicate the internal drive max's out at 1tb, but others have said with special handling I can go up to 8tb, others say 3tb is the limit. Currently everything about the tivo is stock, its never been touched with any upgrades. Its used daily, so should be up to date on software. What are my upgrade options? What software do I need (all the mfs tools seem to be gone)? Is there a step by step on doing this?