Can I paint on stain to make my light cabinets darker, they are wood.

the stain must be removed or the paint will not adhere correctly

Yes, but will require rubbing down first...........

You can stain over stain and change the color with Minwax Polyshades.

http://www.minwax.com/how-to-finish-wood/change-stain-color-with-polyshades/

Make sure to sand the wood first, so the new stain will penetrate. Use a taccloth to remove dust before using new stain

Go to General Finishes website. They have lots of videos and how-to's for just this thing. I just did it with my dining room set - came out great.

Sure you can. Sand the cabinets first. The best way is to remove the cabinets and the hardware, then sand and stain. Stain does not cover like paint. Please try on a piece of wood first.