how to be a boring person

First, don’t pay any real attention to yourself. Try hard to distract your thoughts and emotions while doing as little meaningful activity as possible.
Certainly don’t pay any attention to other people either, but assume that they are there to hear you voice whatever you happen to say. Assume that they will pay as little attention to you as you are to them, so that there’s no point in trying to engage them. If you’re an introvert, simply say as little as possible until they go away; if you’re an extrovert, just speak incessantly while paying no attention to the meaning of your words. This is easiest if you say the same kinds of things that you always say. You might be tempted to gossip – this is fine as long as you don’t slip into actually paying attention to others or, worse yet, caring about them. If one thing slips through the cracks and actually becomes interesting to you, make sure that’s the only thing you ever talk about.
As soon as you wake up, do all the daily activities that you have to do grudgingly – with no care for the reason that you’re doing them. If you have a job, focus primarily on how you can avoid effort, change or any other discomfort.
Should an emotion ever enter your mind – most of all an awareness of something that makes you wonder about the meaning of anything – quickly find a way to stop it by eating something plainly sweet or salty, or better yet, have an alcoholic drink. Or two. You’ve mastered this art when drinking together is the most exciting thing you can think of doing with your friends. If you ever notice being in a rut, add some marijuana, which is especially good for eliminating desires to face up to any reality in your life.
Be careful not to go outside, especially if there is any nature about. Never walk, if you can drive. Keep the TV on even if you’re not watching it – but try to watch it as much as you can. Sit-coms, dramas and reality shows are all fine as long as they are formulaic and don’t trigger any thoughts or feelings. Ideas are inadvisable which is why you should avoid documentaries. And good movies are dangerous because they sometimes accidentally awaken empathy for a character, which could lead to realising that the people around you are humans living out their own stories. Obviously this is why you should avoid novels as well.
The bottom line is that thoughts, feelings and ideas are all potentially disruptive, and so you need to stick with a tiny cluster of familiar thoughts, feelings and ideas. Above all, ensure that no one else is ever allowed to mess with this small and safe familiar world. Or else you might be forced to pay attention.