there is no risk unless you have a good and experienced mechanic.
i am assuming you have drum style brakes in your car. you will need brake rotors, calipers, pads, brake lines, ABS sensor and you will have to modify the ECU to have this done.
unless you have a problem with your existing setup, its not worth the cost.
and whoever said you need brembo cross drilled rotors is obviously not giving the right advice. cross drilled rotors are required for high performance setups...while they dissipate heat from braking quicker, they wear out faster and expensive to replace when done.