I've had the kill switch installed in the past and vouch for its ease of use, functionality and peace of mind (not having to remember to press the TC after every shift from L to H or between 4H to 2H). Having said that, after the switch failed during one of the drives some three months ago, have been using the onboard switch and loving it.
As Gaurav mentioned, step 1 is single press which deactivates TC, step 2 is the press and hold for 5-7 seconds until you see the notification of ESC off on the dash. My Jeep, since its special, doesn't need to be in N to do the above steps, do check yours if its special too
Now comes the cumbersome part compared to a kill switch; one needs to remember to disengage TC/ESC whenever there's a change between 2H, 4H, 4L or if one restarts the engine.
In hindsight, i could have very well saved 400 dhs+++