Our youngest is about to turn four and we've recently made our last big lovey switch .
I think the key thing for us has been being consistent and predictable with the lovey usage. Our girl knows when she can take her blanket/bunny with her into bed but also that it needs to stay there during the night.
Around the same age, our eldest would get really anxious without his comfort object , so we came up with a plan for him to put it on his shoulder or hold it in one hand for reassurance. This worked out okay and eventually he lost interest in carrying his special toy around, which in hindsight made the eventual goodbye much smoother.
The first time you try to move towards the 'no lovey' approach might be rocky but have faith that your child will develop new strategies if you're consistent and gentle. In this instance, we've been using an 'in with you - out on the bed' method . This means our youngest has learned that when her special rabbit goes in with her at bedtime, it comes back to its designated home overnight which she's grown comfortable with.
We used a similar system when moving from a blanket to the rabbit and it did make nights slightly less chaotic. Our youngest does now get thirsty sometimes during sleep so we've just got into bringing a glass of water to bed if that happens now.