Question on Automatic Transmission Fluid Change

The top up portion does not make sense to me.
Car is all back together, ready to refill. I fill tranny through fill plug at top until fluid comes out of the stand pipe. Insert fill plug to avoid geyser, start car & cycle through gears, then top up until fluid spills over the standpipe again.
But How do I top up with the vehicle running if the fill bolt has been reinstalled?!

I assume with the vehicle running the tranny plumbing sucks up a lot more fluid, and is why the pan drains so much before the stand pipe is removed. The only way to fill to the level of the standpipe is to add fluid while the car is running, but the tutorial does not specify how to add the additional fluid. Can I re-remove the fill bolt after the vehicle has been started and is still running?!

Many thanks!

__________________
This post was auto-generated based upon a question asked on our tech article page here: MINI Cooper Automatic Transmission Fluid Change (R50/R52/R53/R56/R57 2001-2015) | Pelican Parts DIY Maintenance Article

[Nick at Pelican Parts]

You will fill through the fill plug. Once you check level, remove fill again, then reinstall fill plug.

- Nick