It's still working here (2DS Sysnand 10.1.0-27E)
You really have to push the L+R good on 2DS.
It also helps to have a pencil on your month to push the power button
Hold L+R+A+D-pad UP - keep holding them pressed and push the power button
You should be in the (recovery) update screens, cancel and you get rid of any update nag for 10.2