That line from the power company pole to your weatherhead is called the service drop.
The service drop is always energized. There's no breaker or switch up on the pole. To de-energize a service drop, they have to come with a boom truck and go up there and detach each hot from the poletop splice.
So yes, the power company must be involved - that can't be avoided.
If you're saying all 3 wires have broken completely off your weatherhead and are laying in your lawn, then call the power company IMMEDIATELY since this is a downed power line that is energized, and can kill a kid. They'll be out fast for that!
You have to check with your power company but usually they want to see proof of a city inspection/approval before energizing equipment.
So your project scope should be to replace the weatherhead. Generally the city inspector won't make you replace a bunch of other stuff too.
If your circuit breaker panel is also as roached and old as that weatherhead, then I very strongly suggest you also replace the electric meter with a "Meter-Main". Why? Because this will let you fully de-energize the tired old main panel, which will open up a whole bunch of options... Some of those options enable DIY work, and other options enable doing the work in "small steps", which simplifies permitting requirements and doesn't require your house to lose power for more than an hour at a time.