A shower drain is a starting point for dirt and debris collection. Soap particles and other bath products can collect in the drain, causing it to run slowly and clog. Sometimes the corks for shampoo and other shower products can fall into the drain and get caught in the trap, which can then lead to an accumulation of hair and other debris. Sometimes the best way to clean the drain is a Shop Vac, which can make drain cleaning work easier.
-Remove the drain cap with a standard screwdriver to remove the screw, which is usually in the center. In some cases, you may need to remove two screws. If the cover sticks, lift it with the blade of the screwdriver.
-Switch on the Shop Vac. Move the end of the pipe around in the drain to provide a better opportunity to vent debris and other items into the drain. Continue vacuuming the drain for at least five to eight minutes to ensure you remove as much debris as possible.
-Put the ear plugs into your ears to protect your hearing from being damaged by the noise of the Shop Vac.
-Insert the end of the Shop Vac hose into the drain. Use an old cloth to fill any space between the hose and the drain. This will ensure better airflow and suction power to pull items out of the drain.
Side note: if this fails then you can always hire a plumber. If you are in the states then these plumbers in Charlotte NC would be a good choice. If you are in a different state then go and look at a plumbing directory for some companies.