Trans flush with no convertor plug...
or "TRUST" the local shop with a trans fluid flusher.
Or you could DIY it.
basically you want the same amount of fluid to go in as comes out.
a sealed system will do this. As old fluid goes into the right sealed container it displaces air which displaces air in the other sealed container and forces new fluid into the transmission.
![1720564909133.png 1720564909133.png](https://www.forabodiesonly.com/mopar/attachments/1720564909133-png.1716274159/)