I used the cabinet transformations kit from Home Depot. It says "no sanding required" but don't be fooled. They give you a couple of green scrubber pads and a can of deglosser. You have to scrub the gloss coat off. It would be easier to sand it.
I jerry rigged a way to attach the scrubber pad to a sander because frankly, it would be easier to sand than it is to scrub away the gloss coat. If you sand it, you only need to sand off the gloss, not all the old stain/paint.
We have A LOT of cabinets...24 to be precise. I needed two of the kits.
Pro tip: Get some heavy duty rubber bands and use them to attach the scrub pads to a sander and have at it. It takes a couple of minutes to do a large cabinet door that way. If you do them by hand it takes a half hour per.