Think I might do a little guide here.
The install is possible on the i30 hatch as I had done this to my 07 hatch
There is no wiring loom, but if you have a couple of hours on your hands and a couple of tools, anyone can do this!
Shout out first to eyecon as he helped me with getting the mirror off [scariest part most probably!]
Ok, first thing is to remove the mirror. There are 4 little 'latches' on the back of the mirror. If you grab a flat screwdriver and pry the top two up and apply a little force, the mirror will pop off.
I recommend removing the wirings for the heated mirror but I am unsure if they are polarised so make sure that you make a mark to remember which wire goes where. I just used some tape and whiteout.
Afterwards remove the screws that are holding the black surround to the backing cover and then the screws holding the backing cover to the inner metal plate.
Fold the light inwards towards the body and through pulling upwards and out, the white outer housing will slip off. It doesn't require much if any force, so if it does, I think you are doing something wrong
Afterwards swap the mirror housing to the new mirror housing!
Afterwards, the method that you run the wiring to the side indicator is your choice but I will show you the way that I did it.
Remove the black cover on the inside of the car holding the tweeter assembly through just pulling towards you. Remove the connecting cable, and then the 3 nuts holding the side mirror to the door frame. Once you remove the wing mirror from the body, remove the rubber black cover on the end of the side mirror.
After this, drop the new wing mirror indicator's cable through the hole that has the current wiring to the side mirror.
At the bottom of the side mirror is a small plate, remove that plate using a small flat screwdriver and pull the cable through and feed it through the rest of the housing.
Afterwards, you need to cut a small V shaped cut on the rubber plating to run the cable through.
Reattach the side mirror to the body and ensure that you don't overtighten with a ratchet for those nuts (speaking from personal experience as I managed to shear one...)
Afterwards, remove the door card [there are multiple threads here covering how to do that] and the first hole directly below the tweeter assembly is covered in a clear plastic. Poke a hole through this and drop the cable through.
Afterwards bring the cable through the side of the door by removing the gromet and run the cable to the side indicator.
Tap the power from there and test your lights! [on mine, the positive and negative wires were switched aka red was negative and black positive for some reason but worked eventually]
Best of luck! Its really not that hard if you have time on your hands. And its best to set yourself a good couple of hours!