Do I need any special tools or hardware to install these?

Installation requires basic hand tools and a socket set. You'll need a hub puller or slide hammer to remove the old hubs; a new axle nut may be required depending on your torque specs — refer to your vehicle service manual for proper fastener specifications and torque values.

Are these sealed bearings or do they need to be repacked?

These are sealed cartridge assemblies — no repacking. Once installed, they're maintenance-free for the life of the bearing.

Can I install just one hub, or do I need both?

You can install one hub independently if only one side is bad. These come as a pair, so if you need both, you have them on hand; if you only need one, order accordingly.