How to drag and drop condition to the Root node in Decision Tree ?

Hi Experts,

I am in situation where I had a decision Tree for determining Collection Step (dunning proposal ) with many conditions.

Now due to Business Requirements changes we need to add a new Root node and the old root node with all existing  Conditions will all be there under the 'TRUE' condition of the New Root node.

I want to change the Existing Tree only. Is there any way of doing this ??

Thanks,

Nilanjan Nag