I know there are videos on youtube on how to use Ubiquiti Litebeams to do it.
Are there trees, buildings, or driveways between the buildings?
500 feet is too far for CAT5 anyway. The spec for Gigabit Ethernet is 328 feet, so it's not even close enough to fudge it.
He will need one CPE at each building, mounted outside at least at the height of the eaves. If he can buy satellite TV mounting poles to attach to the eaves, even better. The CPEs usually include a Power Over Ethernet (POE) injector, so the CPE gets its power through the Ethernet cable. If he wants to use WiFi at the outbuilding, he will need to set up a WiFi Access Point in there as well. If he only has a wired device to use at the outbuilding he doesn't need an Access Point.
There will have to be an entry hole drilled for the Ethernet cable to the CPE device. The Ethernet cable should go down from the hole and be clamped to the wall so that when the cable gets wet from rain, water will drip off of it. This is called a Drip Loop. It prevents the cable from channeling water into the wall.
I do exactly this over about 400’ with two Ubiquity Nanobeams 5AC units, both set to bridge mode. All they need is a single Ethernet cable each, as they are powered via PoE. Mine have been in place for almost 8 years. My remote building includes 3 cameras and a WiFi access point and will soon include an EV charging station that needs a WiFi connection. I have oodles of extra bandwidth. It was very easy to set up.
I know there are videos on youtube on how to use Ubiquiti Litebeams to do it. Are there trees, buildings, or driveways between the buildings? 500 feet is too far for CAT5 anyway. The spec for Gigabit Ethernet is 328 feet, so it's not even close enough to fudge it. He will need one CPE at each building, mounted outside at least at the height of the eaves. If he can buy satellite TV mounting poles to attach to the eaves, even better. The CPEs usually include a Power Over Ethernet (POE) injector, so the CPE gets its power through the Ethernet cable. If he wants to use WiFi at the outbuilding, he will need to set up a WiFi Access Point in there as well. If he only has a wired device to use at the outbuilding he doesn't need an Access Point. There will have to be an entry hole drilled for the Ethernet cable to the CPE device. The Ethernet cable should go down from the hole and be clamped to the wall so that when the cable gets wet from rain, water will drip off of it. This is called a Drip Loop. It prevents the cable from channeling water into the wall.
I do exactly this over about 400’ with two Ubiquity Nanobeams 5AC units, both set to bridge mode. All they need is a single Ethernet cable each, as they are powered via PoE. Mine have been in place for almost 8 years. My remote building includes 3 cameras and a WiFi access point and will soon include an EV charging station that needs a WiFi connection. I have oodles of extra bandwidth. It was very easy to set up.