Hi! I usually just let them in the same area together .... but observe them to see if one is going to be overly aggressive with the other. Hissing, spitting, growling are all to be expected ... but if there is any jumping on and biting ... then you need to separate them and go very slowly!!! Also make sure to pet both of them in front of the other one .... and feed them in separate areas at first! Also, it wouldn't hurt to give them each their own litter boxes at first too! Really, TIME is all that is needed ... and unless they are really agressive with eachother ... they will be accepting in as little as 2 or 3 days! Don't worry .... they WILL work things out and before you know it ... they'll be romping and playing together!!!