You know this type of pot.
Hard to take off tree.
I removed old soil on bottom and cut off big roots.
Can you see? I leave small roots.
Also side and top too.
Take care when you touch root.
Set up new home.
Still I want to cut some roots.
I will about 5 years later….
Also I nip some buds to make balance.
Better before make needles when you nip new buds on Japanese White Pine.