Saw this the other day.
Looking for this one? https://www.hometalk.com/42174851/repurposed-laundry-room-cabinets-with-country-chic-paints
Here is how I painted my laundry room cabinet doors: http://gatheredinthekitchen.com/2015/07/07/laundry-room-makeover-for-under-50/
Basically I primed them and then painted!
You can clean, sand, prime and paint them or you can sand, then restain then seal them. Either way they will look better. If you need specific instructions, let us know which one you want to use. Wishing you the best.
Here is what I did: http://alifeunfolding.com/blog-1/2017/10/12/orc-week-2-updatethe-good-the-bad-and-the-ugly?rq=the%20good%20the%20bad