How to open the built-in sewage outlet of Shenzhen Wanhe electric water heater dscf40-c2a 40 liter storage electric water heater?

This electric water heater needs to remove the cover at the bottom of the electric water heater (the cover is fixed with screws, and the cover can be removed by unscrewing the screws. Be careful when screwing). After removing the cover, you can see the sewage outlet. After draining, remember to put back the sewage plug, and then tighten the screw again to fix the cover. If you can suggest it, you'd better contact the professional master of the manufacturer to handle it at home.