The biggest deal about it is that is seems like nothing, but could still take 30 mins plus to do depending on whether you need to disassemble part of the pedal. Most techs, me included, would do it for the basic 1st-hour bench charge (around £30.00). You might be just as well off getting a mate with a soldering iron to do it.
My biggest concern would be HOW and WHY the led has stopped working - its highly unlikely to have worn out, so that leaves the explanation as a wire coming loose or the pedal has been run with an incorrect power source.
