after they have both been through sufficient quarentine and no problems are up,than you can have them out with each other at the same time
on how to do it: just take them both out, and do what you normally do with one, but with two, unless they seem to be overly aggresive, and one seems like its really stressed, then seperate them
(dont really expect much from them other than maybe crawling over each other though :wink: )