If the tree belongs to city, just call 311. Otherwise you have 2 options: 1. cut it by yourself. 2. hire some contract.
Yesterday, my husband and I just cut a 3 floors high pine in the front of my home. We just left the root there without digging out it. For a 7 years tree, I guess it is not an easy work to remove the root. We put a bird bath on the root and decorated it around with some bush and flower.
I also hired some contractor for removing a tree 3 years ago. The price depends on tree size and location. I paid 500 bucks for removing my tree (I guess it is at least 10 years), which is very very close on my house and my neighbor house. At that time, I ask for the price for the tree in the front of my house, they just asked for $200.
You can find the contractor from the yellow book. BTW, when you hire some contract, please make sure the price include cut the tree and remove the root.