Oh, there are a lot of options to make people install them. The easiest being, make it desirable to have one.
If smartphones are any indication, people would either straight-up not know about the issues with control/surveillance or have them as one factor of many to trade-off against.
And there are likely lots of benefits that brain implants could offer. If we go full sci-fi, some things they could enable:
- Perfect memory (thanks to digital storage, built-in or in the cloud).
- A perfect sense of location (thanks to built-in GPS and a direct uplink to a Maps-like service).
- Automation of tedious mental tasks (thanks to a bult-in scripting engine).
- Perfect control over your emotions.
- The ability to record and replay any experience.
- Telepathic communication.
- Taking part in fully immersive virtual worlds.
- Seamless interaction with electronic devices, to a point where they bahave and feel like a literal part of your body.
- etc etc.
So if you're a rational consumer, your choice is to have all of that and more - or to throw it all away, based on the seemingly remote possibility that the company could monitor or manipulate your thoughts or make you jump out of the nearest window. And the company is giving their strongest pinkie-promise that they would never do such things.
Even if you stay strong, if enough people take up the offer, network effects will kick in and make "not installing" an increasingly difficult choice:
- Employers will take the enhanced abilities for granted, so you'll have trouble getting a job.
- Operating devices could become difficult to impossible because manual controls will be seen as an unnecessary expense by manufacturers.
- You will be socially isolated, because taking part in telepathic communication will be difficult and you plainly can't visit virtual locations.
- etc etc.
If all that's to much of a hassle to you and you just want to force people to get the implants, you can just hire a "private security contractor" (or build your own army) and force people at gunpoint. If there is no state, who is gonna stop you?