When making phone repairs to the jack or the outlet that the phone plugs in to, turn off the circuit breakers that run from the electricity to that unit. This will prevent any type of damage to you and will provide you with the best results overall.
For an affordable repair service, many people turn to friends to have the work done. For phone repair, this can be fine as long as they have worked on the phones that you have, include the style and the electronics that are in the phone you have.