I'm kinda scared and don't know where to start. I really like this tree and don't want to kill it. But I'm not against doing it, just don't know where to start.
It looks like the tree is well established in its pot, and it seems to be healthy. I would do it in late spring or early summer, whenever the first flush of growth hardens off. At that point, the tree has recouped the energy it has expended in pushing out spring growth, and it will have the rest of summer to regrow its branches.
First flush of growth is hardened off. I really like this tree and I'm finding it harder and harder to cut it way back. There's no reverse taper and the branch sizes taper and branch nicely. I'm definitely going to be thinning it out a little more but trying to work with existing structure.