How do add manual transmission fluid to a 1989 Isuzu trooper?

To add manual Transmission Fluid to a 1989 Isuzu Trooper, first locate the transmission fill plug, which is usually found on the side of the transmission case. Remove the plug using a socket wrench and ensure the vehicle is level. Using a funnel, pour the appropriate type of manual transmission fluid into the fill hole until it reaches the bottom of the fill plug hole, then replace the plug securely. Always check the owner's manual for the specific fluid type and capacity.