If the crosspin is held in with a bolt, and the crosspin comes past the ring gear, then they will roll right out. Actually, they have to.
You can't even take the axles out until the crosspin is out of the way.
And you can't take the carrier out until the axles are out.
All the power of the engine has to go thru the crosspin to get to those spiders to get to the sidegears to get to the axles. If you replace the spiders it is best practice to also replace the sidegears and pin. If used then you transfer all 5 pieces as a set.