Ok......In WrpEdit go to the Objects Tab
Find the name of the tree you wish to replace in the objects list and tick the checkbox for it.
Below the list there is a Replace button and text dialog which will now be active.
Type the path and name to your replacement tree in there and press the Replace button.
All instances of the original tree will now be replaced with your choice.
Hopefully.
Be sure to keep a backup in case
Planck