Command to replace a prefab with another prefab in the whole world?

[Flytrap]

I know a command exists that can replace diseased plants with their regular kind. 
Im looking for something similar, but with petrified trees. 
A command that turns petrified trees back to their normal selves.
PLS HALP

[Lumina]

What is the command for diseased plant ? maybe it will help give you a similar one for what you want to achieve.