You heard it before. This oil is for lifetime. Of course they dont tell you the old oil can be one of the reasons which ended the life of you gearbox. Especially with these modules where the oil gets acidic with age and slowly starts to decompose the pcb.
Unfortunatelly it is not designed to make the oil change easy (of course, why on Earth would you try to change the lifetime oil?)
You can find a lot of videos on youtube, how painful it is. This funnel will significantly shorten your suffering.
Print in PETG, vase mode. ramp up the cooling and sloow down at the narrow part (something like 8mm/s)
For perfect function, cut out a small notch right opposite the groove.
Groove should face the back of the car.
Be smart, change your oils regularly!
The author marked this model as their own original creation.