when you buy a new one, ask them how to install it. Bring pictures of your current faucets with you. Or simply go to HomeDepot to ask them. Also check youtube about how to change a faucet.
For the both one, it should be very simple. Just take off the old one and put new one on. You probably need a big size wrench.
For the kitchen one, should be similar unless you want to change the whole.
Bu sure turn off the valve before the work!