Hi
I hope you have considered this well, and checked other employment opportunities etc, and that you have some savings or can live with people who can help you out financially or at least you can stay there for free or cheap... And/or some good leads for new income..
Maybe you could rephrase it a bit, (at least leave out 'for me') might say something like, 'Hi do you have a minute, can we talk?' and then something like, 'This doesn't seem to be working out, would a week's notice be okay?' (Is that in your contract?) and 'I'm sure you'll find someone great for this job.' You could even give them suggestions where to advertise to get people for the position, that's what I did once, and they really did get someone who was quite great that way. At the time I had to concentrate on my studies, and that's what I told them. So they were really nice about it. The idea is to try to keep it friendly, you never know maybe in another career your paths might cross again and they could be helpful..
You might also say stuff like it's about finding (whatever you're missing on the job - eg need for more human contact or less, if you're certain you wouldn't want to work there anymore, or they don't have other jobs that could give you that), or say something about personal growth or personal or family matters or whatever?
Or give another credible half-reason that allows you keep bridges and maybe if really necessary get the job back? (Getting someone new for them may be a bit of a hassle so it might be good to be sort of nice about it.)
I think it's best to 'save face' and allow them to 'save face' too, you never know when you might need a recommendation or reference or networking.. Or you might later do some freelancing or part-time stuff for them, if needed andmutually agreed upon.. There's a guy who says in his book that freelancing/outside work (from his own biz) for the same company he worked for before was much better for him..
You can tell which parts about the job you liked (if any) or just something general.
The boss may ask you what you didn't like and some books or sites say to be cautious with this.. Maybe just say, 'I think it would be a great fit for someone else' and point out your specific circumstances (like needing to focus on the family or your studies or whatever) or something?
If you google 'How to quit in a nice way' a lot of articles come up, so take a look..