1.) Park your Astro on a level surface.
2.) Set the parking brake.
3.) Turn off the engine and allow it to cool down.
4.) Crawl under the Astro and locate the transmission pan. It is the large, flat pan located under the transmission.
5.) The drain plug is located on the bottom of the transmission pan. It is usually a 17mm bolt.
6.) Place a drain pan under the drain plug.
7.) Use a wrench to loosen the drain plug.
8.) Allow the transmission fluid to drain out completely.
9.) Reinstall the drain plug.
10.) Add new transmission fluid to the transmission pan. Check the transmission fluid level using the dipstick.
