here is the instructions, there is a threaded in plug on the passenger side of transmission, you remove this plug to check the fluid level while running.
The oil level control plug (65) is located on the torque converter side of the transmission.
Start the engine and allow the engine to idle until the transmission fluid temperature has reached the value specified.
Remove the transmission oil level control plug (65). See drawing above.
Add DEXRON® III automatic transmission fluid in increments of 0.5 L until the fluid drains from the plug hole.