The first step to reaching the floorboards underneath is to remove the tiles. This will take some simple tools and a little bit of elbow grease, but it can be accomplished without the help of a professional. Depending on how easy the tiles are to pry up, you may need either a crowbar or chisel and hammer to pop the tiles off the floor. The difficulty behind removing the tiles lies with the glue that was used to hold them in place. If the glue has a very strong hold, you may even need to cut the tiles and pry them up piece by piece to get them off without damaging the flooring underneath.
Once all the tiles are removed, you'll likely be faced with the challenge of removing adhesive residue from the wood floors. Depending on the type of glue, this might not be an easy task. Mastic and thinset, which are both commonly used, dissolve when in contact with water, although it could take 30 minutes or more. If you think the adhesive is either of these, lay wet cloths over the adhesive and wait. It should disintegrate, making it easy to wipe away and move on to the next renovation step.
If the glue doesn't soften, try removing it by scraping at the adhesive with a putty knife. If that doesn't work, try loosening the grip of the glue by applying heat.
The key to this trick isn't to apply the heat directly to the glue but near the glue so that it becomes soft and malleable again. Some people succeed by using a clothes iron and having it hover over the glue before attempting to scrape at it again.
If all else fails, run to your local hardware store. You can purchase an adhesive solvent that will break down the glue, making it easier for you to remove. Remember that the solvent is filled with various chemicals, so make sure that the area in which you need to apply it is well ventilated. Apply the solvent and let it rest for an hour before attempting to remove the glue once more.
Before selecting which method you'll use to remove the tile adhesive, assess what type of flooring is beneath the tiles. If it's a beautiful hardwood floor, consider sanding the glue adhesive from the wood floor to keep it in the best condition possible. If you apply harsh chemicals or spend time scraping at the glue, it may damage the wood flooring.