My uncle have a few big ass maples in his yard and he want me to help him take care of them, any pointer on when/where/what to trim? Not sure the kind but they have smaller green leafs, big fat chunk 6-10' tall then a few big limbs split up like....fingers pointing upward with skinny branches(some of them are 10'-20' with shape of an arch) everywhere . They're like 30-40' tall, any things above 15' I won't be able to reach. The goal is to keep them healthy, any trips?