how do i clean the inside water tank of my keurig classic? it's got brown stains.

Those stains are normal mineral deposits from your water and won't affect operation. For basic cleaning, you just wipe it.

1. Unplug the brewer and let it cool.
2. Press the "PRESS TO OPEN" button and lower the handle completely. The water fill lid will pop open.
3. Inspect the hot water tank area and clean it with a damp, lint-free cloth. That's all you need for stains.
4. Close the water fill lid when you're done.

IF THAT DIDN'T WORK: If you see white, crusty deposits (scale), you need to descale the brewer. That's a different process using vinegar to dissolve calcium buildup, which can hinder performance if left alone.

HEADS UP: Never immerse the base unit in water. Just use a damp cloth on the housing and external parts.