Swaddle Transition Help

Caitlin

So my 9 week old isn't rolling over yet but starting to kick his legs like crazy like it might be coming in the next few weeks. We want to start to transition him out of the swaddle so its not a sudden need to go cold turkey when he masters rolling. Any advice? One arm up to start? Im terrified to ruin his good nighttime sleep 😭 we are using the nested bean zen one if it matters.