You have a valid point. And the risks become ten fold if someone was just trying to wing it without thoroughly viewing all information available and taking their time. There are risks, geniune ones, especially considering the antenna wires when reassembling.
That said, if you are wanting to save money and do the upgrade yourself, There is plently of information to tell you how to do this step by step safely.
Not saying accidents won't happen, but I think the large majority of upgrades by people who educate themselves ahead of time and take it slow, have been successful.
To try to convince anyone this is a full-proof self upgrade would be foolish.
To try and convince someone that the benefits outweight the risks, well that's all subjective isn't it? Hence, why we're still talking about it.