Preparation

• 1). Empty and thoroughly flush the black-water tank.
  
  
• 2). Turn off the main RV water hookup.
  
  
• 3). Disconnect the toilet water connection, using pliers if necessary.
  
  
• 4). If this is an electric toilet, disconnect its electrical wiring.
  
  
• 5). Place plastic sheeting in the bathtub or over the space where the toilet will be placed temporarily.
  
  

Toilet Removal

• 1). There are usually two bolts holding down the toilet. Locate them---they may be hidden under caps.
  
  
• 2). Pry the caps off using a flat-head screwdriver. Place the small caps somewhere safe---an egg box or compartmentalized craft box works well.
  
  
• 3). Remove the bolts. If they are awkward to reach, a socket extension may be required. Store the bolts carefully.
  
  
• 4). Grasp the toilet on both sides and lift upward. If it is reluctant, twist it slightly until it comes off.
  
  
• 5). Place the toilet on the protective sheeting.
  
  

Inspection

• 1). The rubber gasket, or toilet bowl seal, is now visible. It sits between the mounting flange and the toilet.
  
  
• 2). Lift the gasket straight off the flange. You may need a flat-head screwdriver to pry it off; twist the gasket to break any adhesion.
  
  
• 3). Place a sheet of aluminum foil over the sewer opening to prevent odors and loss of small parts and tools into the tank.
  
  
• 4). Clean the flange and toilet base area thoroughly.
  
  
• 5). Inspect the toilet area for rot and stains. If any work needs to be done, make a trip to the hardware store and take care of it immediately to avoid damaging your new seal.
  
  

Replacement

• 1). Lower the new gasket over the flange. If desire, apply plumber's sealant for extra waterproofing.
  
  
• 2). Place the bolts in the location where they will meet the toilet.
  
  
• 3). Lower the toilet down over the bolts. This task is easier with two.
  
  
• 4). Check that the bolts are back through the holes and that the toilet is seated level.
  
  
• 5). Tighten the bolts and replace the caps.
  
  

Final Steps

• 1). Hook up the water and, for electric toilets, electricity.
  
  
• 2). Check for leaks.
  
  
• 3). After a day or two, check the toilet bolts and tighten if necessary.