So this is the unit you've been trying to remove



If your like me you could try and repair it. But having looked at it I'd say mine has water corrosion all over it, So I'm going to call hyundia tomorrow and ask for a price of a new one.

If you want to open it, you need to remove the small screws around the cover, then lift the cover off.



The next bit took me a bit of time to work out.
You need to remove the connector by pulling it out, there are a couple of tabes that need to be pushed in either side, then grab the connector and pull like the pic shows

now the PCB will drop out


Not the greated shots I'm afraid the old camra phone ant too great



From an electronics perspective youve got a relay, two transistors, a few diodes (maybe a zener) three caps and a few risitors.

Looking at mine I'd say the most likely fault is the contacts to the connector block which have corroded to buggery! You can try sanding these back and getting bright shiny metal again but mine is prity bad.
Next mostl likely electrical fault would be the switch contact, these are the circular bits near the top and should be un corroded shiny metal.

Then the rest of the pcb, which again for me is so covered in water damage that I'm not too optermistic