Yeah I did this on my old 240sx and it’s REALLY simple. The hardest part was getting the soft lines off the hard lines. A lot of the times you have to torch the nut to losen it. If you wrench on it to hard, you’ll crack the hard line.
Fronts are MUCH easier to do then rears and unless you guys plan on pumping more the 450+ hp, just do a front brake upgrade, buy better pads/rotor’s for the rears. Remember 70% of the braking is done up front and you also won’t need to change the brake master either ;).
Also unless your running S14 stock rims (and even then don’t quote me) stock S13 rims DO NOT clear the larger calipers. Theres 3 options here;
Buy 3 mm wheel spacers
If you can only find 5mm spacers also buy longer wheel studs too as theres not enough thread to secure the lug nuts on properly.
Grind down the caliper - NOT RECOMMENDED!!!
Basically if you have everything you need before hand, this upgrade requires only moderate mechanical skills and some patients. Should only take a couple of hours baring any prob’s. Have a friend around though to assist you in bleeding the brakes. You only need to bleed the fronts so no biggie but start with the right front.