This procedure would only be taken if the surface is badly damaged or painted and beyond light restoration. Remember, patina or a finish that has been acquired over many years through the build up of dirt and polish, is the "guilding" on old furniture and is the key to it's beauty. Destroy that and it is lost along with most of its value.
There are a number of commercially prepared chemical strippers that are suitable for use on furniture. Names like Nitromoors or Liberon. These can be purchased from DIY or hardware stores.
These strippers are designed to remove practically any finish that you are likely to find on furniture, including water based paints and varnishes. They mainly contain substances that burn the skin and give off fumes that can be unpleasant. Make sure that the area in which you work is sufficiently ventilated. Wear goggles and strong gloves when using these substances. Check the instructions supplied with the stripper.
Using a brush, paint on a liberal coat of stripper. Fill crevices and corners thickly.
Leave for ten minutes or so until softened. Try scraping a small area first. A paint scraper is ideal. Coat again if it doesn't show the wood underneath.
Start to scrape off in the direction of the grain, wiping off the residue from the scraper onto newspaper. Continue until completely clean and all of the coating has been removed.
Moulding and Corners
Use a sharpened piece of wood to scrape out the softened finish left in the cracks and mouldings. Clean thoroughly with fine steel wool, turning it when it becomes clogged with varnish or paint.
Finally rub all over the area with the fine steel wool. This will produce a smooth surface ready for it's new finish.
See also French Polishing