Change a tv on the wall for a new one and make sure it works

I have a tv thats been on my wall in the living room for a few years Over the years the wires have gradually come out, I have now bought a new one and would ask if anyone could take this one down and fit the new one up. I,m not sure wether I need an expert in that field or a general handyman, maybe you could tell me, and also let me know what sort of price I would be paying please Many thanks Barbara Burbage