Yes, the oil in an automatic transmission can be drained. The procedure for changing automatic transmission oil depends on the specific make and model of the car. However, in general it includes the following steps:
1. Raise the vehicle on a lift or place it on a level surface.
2. Find the oil drain plug on the automatic transmission pan.
3. Place a container under the plug to drain the oil.
4. Unscrew the drain plug and allow the oil to drain into the container.
5. Once the oil stops leaking, tighten the drain plug.
6. Fill the automatic transmission with new oil through the upper filler plug.
7. The oil level should be checked using a dipstick or diagnostic tool.
8. Tighten the filler plug.
It should be noted that some automatic transmissions have a complex design and may require the use of special equipment or software to change the oil. Therefore, it is recommended to contact a qualified mechanic who has experience in servicing automatic transmissions.