I purchased this on sale at a steal of a price to upgrade the 1 TB drive in our TiVo Roamio OTA because these have a WD Red drives inside. In doing so I voided two warranties at once, but totally worth it! Once I tested that the WD drive was functioning properly, I shucked the drive by using a set of spludgers designed for opening electronics, there are 3 clips on each side once you have something in those spots to keep the clips from engaging, the drive slides out very easily, I can't even tell I opened it. Take the 1 screw out of the back of the TiVo, pop the lid, remove the 4 screws that hold the drive in, then the 4 screws that hold the rails on. Replace the drive, power up the TiVo and wait for it to get to the setup screen. This takes about 5 to 10 minutes because the TiVo is formatting the drive during the startup process, I didn't time it so it may be longer, maybe shorter, be patient. Shut the TiVo down, take the drive back out, connect it to your computer via the USB circuit board that came out of the drive case, then use MSFRTools 3.2 or later to expand the drive so the TiVo sees all 8 TB, this is called "blessing" the drive. Reinstall the new drive, button up the TiVo case, complete the setup on the TiVo and you are done! Total time if you don't mess up, about 45 minutes until the TiVo is back up and running. Extremely easy and cheap way to get 8x the space on your TiVo. You will loose all recordings and OnePasses doing this, I had none because I was anticipating this upgrade so we did not schedule anything to record. If you want to keep your recordings, you can either copy the recordings to your PC or another TiVo or clone the drive. You are limited to a 4 TB drive when cloning as this is the largest drive the cloning utility can handle but you don't lose any recordings or OnePasses you have setup. I did the clone method on our first TiVo. The clone process takes a bit longer and will require that the drives be connected to a PC and that you have a boot drive for the utility. Takes about 2 hours, but totally worth it as well.