Your use of the passive infinitive means you're going to get your LBS (or other) to do this for you; right? So labour and cables? Phone your LBS and ask?How much should I be looking at paying for a set of [brake and gear] cables to be replaced on my 2016 giant defy
Just a few quid from somewhere like Decathlon unless you want to spend more on premium brands.
Don't forget to grease them and buy some of the little end caps to stop fraying. You should be able to cut the cables with a decent pliers which has a cutter.
Remove the pads and inspect them, if they're down to 1-2mm replace them.
It's true you really need a dedicated tool but I've had good results with a quality plier. It's make do and mend down here.