50fps to 25fps

Hi guys,
Accidentally edited a whole project in 50fps project settings instead of 25. I’ve looked in project settings for an easy change back, but can’t seem to be able to do it. Any ideas how to not have to start the whole project again and get my timeline into 25fps? Thanks

Drop that timeline into another timeline with 25 fps and change re-timing to nearest.
DR will drop any other frame.