Wiper arm removal tool

[RafflesNRH]

Can anyone suggest a suitable tool to remove the front windscreen wiper arms please?
ISTA states a 'special tool' (aren't they always!) # 2 348 527, but I can't seem to find one online, and a forum search doesn't seem to shed much light either.
How do you guys manage to get them off without using a hammer and chisel?

 

[EvanstonI3]

I've just put them into position and then used my hands.

 

[Mondomensch]

I've just put them into position and then used my hands.

Does that work for removing the arms rather than removing the blades?

 

[EvanstonI3]

Does that work for removing the arms rather than removing the blades?

Oh good point. I read “blades”.
edit to add: All the wiper "arms" I have pulled off other vehicles required a small pry bar lever to initially release them from the splined shaft after loosening a set screw/bolt

 

[eNate]

I have a generic (Lisle) wiper arm puller tool, but have never used it on the i3.

Here is an image of the BMW tool so you can make an assessment of which generic tool might fit the task.