Remove the shower head from the shower. If it does not come off easily, use pliers or vice grips to unscrew it off. Now remove the cover from the shower head. The cover is the shower screen which contains the deposits. Rinse the cover in water to get rid of all large contaminants.
Warm 2 cups of vinegar in a pan. Turn off the heat and set aside. If you have already removed your shower head, you can simply place it in the vinegar. Let it soak for twenty minutes.
If you have been unable to remove your shower head, fill a plastic bag with the vinegar. Place the bag on the head of the shower. Use rubber bands to secure the vinegar filled bag to the shower. Make sure that the head is completely immersed in the vinegar. Let the shower head remain in the vinegar for an hour. If the sediments are very stubborn, you may consider leaving it overnight.
After you remove the shower head, use a brush to clean off any remaining sediments. You can also use an old tooth brush. If you had taken off the shower head, re-install it after rinsing with clean water. Adjust the head properly to prevent any leakages. Wash the shower overall with water.