To clean a Keurig coffee machine, the process generally involves cleaning removable parts, wiping down the exterior, and descaling the internal components to remove mineral buildup. Key steps include:

1. Unplug the machine and disassemble removable parts such as the water reservoir, reservoir lid, drip tray, drip tray cover, K-Cup holder, and water filter (if applicable). Soak these parts in hot, soapy water and then rinse them thoroughly. Some parts may also be dishwasher safe.
2. Wipe down the machine's exterior with a damp cloth and all-purpose cleaner to remove coffee stains and spills.
3. Use a paperclip or cleaning tool to clear coffee grounds from the K-Cup holder needle and tube.
4. Descaling: Fill the water reservoir about halfway with white vinegar (or use a Keurig descaling solution), then fill the rest with water. Run multiple brew cycles without a K-Cup inserted, emptying the cup each time until the reservoir is empty. This process removes calcium deposits and mineral buildup inside the machine.
5. After descaling, fill the reservoir with fresh water and run several brew cycles to rinse out any vinegar or descaling solution residue.
6. Let the machine rest for about 30 minutes during descaling to allow the vinegar/solution to work effectively.
7. Reassemble all parts and your machine should be clean and ready for use.

Perform this cleaning routine every 3 months to maintain your Keurig's performance and taste quality. Additionally, wipe the exterior and clean removable parts weekly to prevent buildup and ensure good hygiene. This comprehensive cleaning guide is based on Keurig manufacturer recommendations and expert tips.