My 2010 KIA Forte LX has no power lock from stock, but it has wires in doors. Is it possible to put lock actuator from EX model? Or in any other DIY way? I've checked a lot of forums, but there is no clear info. Dealership and auto shops want $500-700 for this.
In theory it should be possible, if the higher-spec models had them, however it may depend on the various computers in the car.
The wiring will all be there (as it isn't worth them making different wiring looms for different models), however the software might not recognise the actuators - and you can't simply swap over the BCU (Body control unit, i.e. the computer that controls things like door locks, windows etc) as it'll be coded to the particular car it is in.
The Forte LX mode uses a cable setup to work the door locks. While the EX uses rods. It is possible but, it would take some work to figure out a way to connect the door handle (interior) to the lock assembly. Next you would have to find a way to provide these locks with power since the harness is not the same in both models.
On the software side both Body Control Modules are the same part number so it's most likely that if anything it's just some coding that would have to be done.
All-in-all I wouldn't call this a "DIY" job. It is much more involved than an oil change. Of course, it could be "hacked" together and done cheap. But, if you want it done right, then the dealership would most likely be the best bet. (I say dealership because they have the most resources)