When Madara was trying to stop Obito from warping, he was going to use Limbo, but then decided against it because Obito still had the Rinnegan.
The natural assumption was that Limbo was so strong it would damage the Eye. Now that we know it's creating a Shadow Madara. Surely the shadow madara could remove the Rinnegan without damaging it.
Since both Obito and Madara's rinnegan where originaly Izuna's eyes, Obito should be able to see into Limbo and see the Shadow Madara.
And of course, Obito has his staff. That's SO6P Chakra. So he has everything nececarry to hit Shadow Madara.