F.O.G. Horn 5 provides a step-by-step guide on how to remove, disassemble, clean, lubricate, and reassemble the bolt carrier group in a Tokyo Marui MWS. He begins by listing the necessary tools and materials, including needle-nose pliers, a metric Allen key set, flathead and Phillips head screwdrivers, a hook tool, pliers, a pin punch, a ballpeen hammer, a cleaning rag, Super Lube multi-purpose synthetic grease, a toothbrush, a cup, isopropyl alcohol, a bag, and a bin. The disassembly process involves removing the bolt carrier from the upper receiver, followed by the roller bolt, screws on the nozzle guide, the nozzle itself, and the nozzle return spring assembly. The nozzle and its return spring are further disassembled into their individual components.

He then details the cleaning of all parts with isopropyl alcohol and the subsequent lubrication using Super Lube multi-purpose synthetic grease, specifically advising against the use of silicone oil. The reassembly process involves putting the nozzle back together, followed by the entire bolt carrier group. Finally, the bolt carrier group is reinserted into the upper receiver, and the lower receiver is reattached.