slowly and very, very carefully! At first, Smokey (the bigger one) wanted to eat the little hatchling Bandit, but eventually (months later) they started to act like true siblings. They love each other, but it is apparent that they get on each others nerves sometimes. I cannot and do not keep them in the same cage... (I'd be worried for their health if I did that, they'd most definitely eat each other then!!!) But when they are out of their cages they interact just fine.
Some people would call it "teasing" but I do not, I would let them sit close, if one or the other tried to bite, or attack (you kno, they get that look in their eyes that they get when they are eating crickets!) I'd pull them away. Eventually it all worked out.