I use these led reverse lights
https://www.amazon.ca/dp/B09Q3B27D5?ref=ppx_yo2ov_dt_b_fed_asin_title
They are very bright which helps quite a bit at night as the rear window is tinted. When looking for led reverse lights just look for any led that are W16W. The max watts for reverse lights is 16W, this is the watt usage of the stock/oem reverse incandescent lights. Leds rated for W16W will usually be using way less watts and higher brightness. For the product I used, they rated the power usage at 7W.
For pretty much every light that isn't a signal light, using a light that uses less wattage than the specified rating will work. Signal lights requires a certain amount of wattage to prevent hyper flashing.
Installation is actually pretty simple. You'll need a plastic trim tool remover, if you don't have one then a flat head screwdriver will work as well.
1. Just pop the 2 trim cover on the trunk door and it will give you access to the reverse lights.
2. To remove the reverse lights from the housing, you just need to grab the ring like knob and turn counter clockwise. The actual movement isn't much, no more than a quarter of a circle turn. Once it's unlocked just pull it out carefully.
3. I would suggest using gloves or some cloth/paper towel when handling the incandescent light bulb. You just pull it away from the connector and it should pop out.
4. To install the led light just pop it back into the connector. One caveat with led lights, they are directional in nature, meaning they have a positive and negative connectors. So if you plug them in the wrong way just pull it out and flip it around.
5. Before you put everything back together, test your installation, have someone shift the transmission into reverse. If by yourself, make sure the parking brake has been activated.
6. Perform step 2 then step 1 again but do the opposite of what you did in these steps.
The biggest concern you should have isn't the installation but buying quality led lights. Buying poor quality led lights could overload the circuit and blow a fuse in the best case, worst case, fry a wire connection which will cost a lot of money to repair. That being said don't let this scare you too much, a number of us on the forums have used various led lights in our Outbacks without issue so you have some products that will work fine on your Outback.