I do not free feed, I haven't for years. The first couple days are the hardest on the kitties because they do not realize that they need to eat NOW or wait. But they will adjust quickly, trust me. I feed morning and night, as close to 12 hours apart as my schedule allows. They get a measured amount of food depending on their needs. This will vary between cats and between the different types of food. When in doubt, ask the vet. I personally do not allow the kitties access to each others dishes which would defeat the purpose of measuring, they will just switch bowls. With only 2 you should have no problem separating them. (If I can separate 14, you can do 2). Leave the food down for anywhere from 1/2 to 1 hour then pick it up. Do not be shocked that they do not eat their first meal. And their second meal will also probably only be picked out. But soon they will come to know that they need to eat NOW.
Trust me, it is a very healthy way to feed. You will be able to keep them at a proper weigh. You will be able to feed them different foods if that becomes necessary. And you will know immediately if one stops eating as a sign of illness.
Best of luck.