The document describes the step-by-step technique for placing a cement plug in a cased or open hole. The process involves running drill pipe to the desired depth, circulating mud, pumping a pre-flush/spacer ahead of cement slurry to avoid contamination, pumping the calculated volume of cement slurry, pumping an after-flush behind the slurry, displacing with mud to balance the plug, slowly pulling out the pipe above the cement top, closing the BOP, establishing reverse circulation to reverse out excess cement, stopping circulation and opening the BOP, and further pulling out the pipe for safety.