The first answer was not much help, since the iFixit teardown is for the FreeAgent Go (a docked USB portable, where the FA Pro is a multi-interface desktop external) and the YouTube videos were for the 'USB' and 'Desk' models of Seagate's FreeAgent brand. That's a bit like offering teardowns for random types of Macintosh when someone asks for how to open a mid-2007 20" aluminum iMac. Actually, it is a LOT like that, because in both cases the functional answer is very specific to the model, may vary by obscure revision cases, and ultimately one may well regret the attempt. The FAPro has no obvious means of gaining access: no visible screws, no soft spots under the SN label, case seams that appear to have been designed to always be razor-tight with soft plastic on one side. Seagate's way of saying "Go ahead, void the warranty. We will know!" Personally, I'm about to do that to mine because the warranty is years gone, the device went silent in an odd manner, and it was my "big dumps of stuff I don't want to wast...
If all you have are Phillips screwdrivers, be very careful with the screws at the split of the bottom case and all of the internal ones. You may have to drop to a Phillips #000 if you don’t have a JIS #00, which appears to be the correct tool for them, based on the actual fit of the bits in my (iFixit) set.
Note that the subwoofer case has 3prongs through which the camera cable is threaded. Remember to re-thread that cable through the prongs when re-assembling.
If you’re replacing the subwoofer, you DO need to remove the left screw but not the right screw. This is fortunate, because if you are stuck with a Phillips #00 instead of a JIS #00 screwdriver, you may well strip the heads of these screws.
You can get away with a Phillips #00 for many of the screws involved but the 4 at the bottom case split are likely to strip if you don’t use a JIS #00 or, in a pinch, a Phillips #000.
If all you have are Phillips screwdrivers, be very careful with the screws at the split of the bottom case and all of the internal ones. You may have to drop to a Phillips #000 if you don’t have a JIS #00, which appears to be the correct tool for them, based on the actual fit of the bits in my (iFixit) set.
Note that the subwoofer case has 3prongs through which the camera cable is threaded. Remember to re-thread that cable through the prongs when re-assembling.
If you’re replacing the subwoofer, you DO need to remove the left screw but not the right screw. This is fortunate, because if you are stuck with a Phillips #00 instead of a JIS #00 screwdriver, you may well strip the heads of these screws.
Just “4 small tin marks” is what the the motherboard half of the subwoofer connector looks like.
You can get away with a Phillips #00 for many of the screws involved but the 4 at the bottom case split are likely to strip if you don’t use a JIS #00 or, in a pinch, a Phillips #000.