It's relatively simple to replace a broken sprinkler head yourself.
Check with the manufacturer for the correct replacement head. Be sure the water is shut off.
Keeping an eye out for buried pipes, carefully dig around the head. Turn the head counterclockwise, being careful not to break the pipe.
Remove the old head and any debris. Apply Teflon tape to the threads and screw on the replacement head. Check for leaks and adjust the spray pattern.
Refill the hole; the top of the irrigation head should sit no more than a half inch above the ground.