Back brakes are SUPER easy, don't even need to remove rear wheel. It's like a 10 minute job to drop pads push the pistons back in, and then go for a ride.
Don't use your rear brake for a bit and stop and verify the smell is gone. If it is gone, cool, you know you have a sticky rear caliper. Rebuilding is very easy and not very expensive, schedule an afternoon and do it your self.
Just ensure your comfortable bleeding brakes, and don't get brake fluid on anything.
Is your bike ABS? If it is, go to the dealer or buy the dealer tool online, it's required to bleed ABS.