Good question. Check out the two links in my first post. The Tesla Offer webpage (Post #1) includes an installation video on YouTube.
And that same Tesla Offer website (in Post #1) includes a page of instructions (for the latest Mark 3.0 version) here:
I have never done it, but I've read the instructions and watched it performed online at a couple of sites. For additional information, skim the posts by many TMC members (in the Thread above) who attempted the installation.
My guess is that if a person (a) is handy with common tools, (b) enjoys working on autos (including automotive electrical wiring), and (c) is patient and careful to follow the instructions, then such a DIY'r should be able to install the power frunk themselves in maybe an afternoon or less. However, be aware that some people, as is always the case, run into problems and need installation help. I would NOT attempt this job if the subject Tesla is your only car. From experience I know it can be easy to break or lose small nylon/plastic connecting devices when you remove them (for example, when taking out the frunk tub), which then have to be replaced. So familiarity, experience, and confidence working around autos is probably all-important. (On the other hand, this project might be that perfect time to inspect/replace your big Tesla air filter.)
I have (or used to have) those abilities, but I may still choose to have it professionally installed by someone with first-hand experience (a) with this particular product and (b) with installing it in my particular model of Tesla. For ~$200 it will be worth it to me to have a professional ensure that it is installed quickly and correctly, and to stand behind his/her work. Just being cautious.
In the end, I think having a powered frunk will be an outstanding feature, and it will help protect what I hear can be a delicate hood against damage from being closed incorrectly.