1. Determine the type and location of the sewer opening, and prepare corresponding tools such as wrenches, screwdrivers, or specialized sewer opening keys.
If the sewer opening is fixed with screws, use a screwdriver to rotate the screws counterclockwise to loosen them. If the opening is locked, use a key or wrench to turn it clockwise to open it.
3. Gently pull or rotate the drain opening cover to ensure that it does not damage the surrounding structure. If necessary, clean up the debris around the opening.