Hi Diane, here's a tutorial: https://www.diynetwork.com/how-to/skills-and-know-how/electrical-and-wiring/changing-a-light-switch
Make sure and shut off the breakers first and then you unscrew the faceplate and then the switch. Disconnect the wires from the old switch and put them on the new switch. Then put on your new faceplate.
You need someone who can do electric .take cover off then shut off main power switch.then unscrew the two screws and the switch will come out be careful the red wire is hot you will get a shock then put new switch on the two screws tighten up and replace plate
Keep in mind that while older homes were built with toggle switches, (first picture below) they can now be replaced with the newer style rocker switches (second picture below) just as easily.
Rocker switch screwless (screws that do not show) wall plates come in different gangs, and colors. They are easy to put on, as the cover simply snaps into the backing.
I saved on the cost of replacing my covers with new ones. Remove the covers (you can do them yourself). Set them on newspaper outside. (spray paint them on a calm day of course).
I just spray painted them the color I wanted. Let the first coat dry completely and spray a second coat on them all. Easy job. I spray painted my multi plugs to match my light switch and electrical covers as well. One can of paint goes a long way. I'm a female and it doesn't take a rocket scientist to remove the covers yourself. I'm sure you have enough common sense not to put a screw driver inside the electrical part of the switch or plug. You are removing one tiny screw.
Tip: Put the little screw back where it came from so this way you wont lose it. Just remove it when your ready to replace your newly painted cover back on.
Have fun spray painting. Slow and easy wins the race. If you rush it when your painting you will get runs. You want a beautiful clear, clean shine that looks store bought.
If you do not want to hire an electrician you can buy (I ordered them from Amazon) a cover for both the light switches and wall plugs that actual just cover the existing switches and plugs. They came in white. They are paintable if you choose to match wall paint.