First, you should consult with your neighbor by verbally asking your neighbor in a nice way to trim the tree. If the neighbor refuses or neglects to trim the tree, then you should send the neighbor a certified return receipt letter again requesting that the tree be trimmed as the tree is causing a nuisance (leaves falling onto your roof and yard) or that the tree poses an acute and chronic danger (damage to property and injury to person). It would also be helpful to obtain a letter from an...