Patience and 2 small persons to get into areas where the human arm was never meant to go.
The job isn't that complicated but does require patience and time to complete. Drain the master cylinder as much as you can to make less of a mess and if your still running Dot 3 fluid remember that it eats paint so protect your floodboards.
My suggestion would be to do the entire system at the same time, that way your starting from square one on everything. The brake system needs to be 100% reliable all the time. Here's your opportunity and the cost differential isn't that great. Wheel cylinders are usually under $25. BE SAFE