My two were introduced at the glider rescue we adopted Simon from. It took about a half hour or so. Initially they ignored and avoided each other until we put them on Darrin
then all the sudden Leela grabbed Simon's tail licked it and buried her face into his tail rubbing it all over her face, was soooo funny
lol Simon groomed her back a little bit then they both went right in the bonding bag together.
I had washed the cage thoroughly and removed anything from the cage that might hold Leela's scent after washing before we brought them home. The cage was to be neutral smelling as much as possible, we put a new cage set in the cage as well. When we got home We put the bonding pouch in the cage and they have been together ever since. For a couple days Leela had trouble "sharing" food, but quickly got over it. Simon crabs at her a little bit in the sleeping pouch, even now 4 or 5 months later he still does lol but it's only once or twice if she wakes him up.
Over all they get along like they have always been together. The toys that we removed were put back in once Simon started marking things as his. By then Leela's scent on the toys wasn't an issue anymore an no one got protective of them. She was a tad protective of all her toys until we got Simon. They both share everything pretty well with each other.
I think making the cage smell as neutral as possible helped a lot, it let Leela know she had to share her space and toys and it let Simon know he could make this his home without feeling like an intruder or outsider.