Your'e in for a lot of work.
You can use a paint stripper. I go for the strong stuff, rubber gloves and ventilation.
You can try the less toxic citrus based stuff.
Use as little water as possible to rinse the stripper off.
You will still likely have a lot of sanding to do, if they are basically flat, it won't be too hard
If there are a lot of details, bevels and such it will be a lot more difficult.