Step 1 - Removing The Water Stain
If water has simply stained your floor, you can repair the stain without a great deal of effort. Simply sand down the hardwood boards and use oxalic acid in crystal form to remove the stains. After that you can re-stain and then recoat with the sealer of your choice. However rarely is removing the water stain simply the least of your worries. If there is significant warping, you will need to remove the hardwood and replace.
Step 2 - Remove the Damaged Boards
Even if there is slight warping, you will neeed to remove, replace and refinish the area, because overtime the floors will get worse. It is difficult to relace boards in the center of a room, so unless you are a professional, you will probably need to pry up boards to the wall.
Step 3 - New Boards Installation
Once you are ready to install the new boards by clearing out the damaged wood boards. It is very important to get the same grade and type of wood that matches your current installed product. Before installing the wood must be acclimated to the environment, this ensures that it will fit in with your existing wood. Follow the installation directions for your particular product.
Step 4 - Floor Sanding
Once the floor is installed, you should sand the entire area so that the entire floor surface new and old wood matches.
Step 5 - Stain the Hardwood Floor
After sanding you can stain the floor.
Step 6 - Finally Finish the Floor
Once it is sanded and stained, add a finish, check out our floor finish page for info on which finish to choose: http://www.olympichardwood.com/Floor-Finishes-Comparison-faq.aspx