Step 1
Locate the drum trap that is attached to the bathtub or shower sewer line, usually in close proximity to the drain hole. Feel the top end of the drum trap for the lid's central nut. The lid and nut may or may not be visible, depending on where it is installed.
Step 2
Place the jaws of an adjustable wrench around the lid's central nut, and turn the wrench handle counterclockwise. If the lid won't budge, wipe off all grease and dirt from around the lid's rim with a rag.
Step 3
Apply an ample amount of lubricant spray all around the lid's rim and wait 15 minutes for the spray to work its way into the lid's threads. Place the wrench back onto the lid's nut, and turn the wrench handle counter clockwise. Apply more spray if the lid won't budge, wait another 15 minutes and try the wrench again. Repeat this two-fold process until the drum trap's lid loosens and can be removed.