OEM Remote Start

Imagine my surprise when I discovered that my 2016 Prius V Five does not have remote start! We're are in the midst of a massive heat wave, and seeing as I bought this car to cart my dogs around, I am now looking at remote start options. I have ceramic tinting on my windows, fans attached to their crates, and use a sun shield, but unfortunately having no shade to park under means hot car.

We own a 2016 Highlander as well, and I like to cool down the car on these type of days for 5 minutes or so before I load the boys up.

So I found this part on Toyota: PT398-47121. I used a Toyota parts website to order another OEM product and it worked well.

So here's my questions:

1. Is this all I need to purchase to get the remote start?
2. For a non-mechanically inclined (yet able to read and follow directions), how hard would it be for me to do myself?
3. Seeing question #2, how badly could I mess this up? Trying to see if it's worth it to pay to get it professionally installed.

Thank you, as always, for your input. I'm pretty new to all this, but have been researching the crap out of things!