Between 2 - 4 months of age your baby may begin to show signs of rolling, while it can take a bit of time for your baby to master their rolling - it's important to remove the swaddle once the signs are evident to ensure that if bub rolls in their sleep, their arms are free help raise their head / lift up.

Once your baby is showing ANY signs of rolling there's untortunately no time for a 'transition' you should be going straight to an arms out sleep sack or suit. This could be bub getting up not their side or trying to do this during floor time, or just rolling one way but not the other. If you prefer, you can go with a transition swaddle if your baby isn't rolling or showing signs of. These give you the freedom to let one arm out at a time over a few days.

Go straight to an arms out sleep sack to avoid delaying the process! The first day or so may be a little unsettled and require some resettling and hands on from you at sleep time, but it shouldn't disrupt things for more than a few days to a week. It truly comes down to temperament of your little one and how they adapt to changes. If you can see they aren't oo bothered by change, remove instantly. If you see your little one doesn't respond well to change, start before you see any signs and really give them that opportunity to adjust at a rate they are happy
with Slow and steady!