Upgrade Hard Drive tivo roamio Plus

Have the plus and want to upgrade the hard drive to 4tb. I have done some research but have a few questions. Is the 4tb now as easy as the 3tb? just pop it in? If so what kind of prepping do I do? Would I format fat32 or NTFS? Also I se the AV-GP WD hard drives. Is that what is in there now? Can I simply use a WD green?



Thanks