There's A Small Pimple-like Spot On My Eyelid's Lower Edge. I Can't Find It's Centre. Looks Like It's Under The Skin. How Can I Remove It?

This could be a stye, which is a bumb on either your upper or lower eyelid, caused from bacteria, stress, poor nutrition and even sharing makeup.
While most styes will drain on their own, this process can take up to one week. Styes can also be treated with a warm cloth, or ointment from your doctor. Even though a stye is technically a pimple and can be popped, doing so is not recommended.

Yes like diamond said, use warm compresses, as warm as you can stand. Do this at least 4 times a day. Sounds like you have a sty in the eyelid. It can be painful but is seldom serious enough to need doctors help. If it gets downright painful, do see a doctor.

Try using warm very warm compresses.. It should come to a head and give you some relief.. I hope this works. It did for me.

I have a tiny white spot on my lower eyelid and my eye looks red under the eyelid

You may laugh but try it ......pull out your eye lid rub a gold ring on it for 20 seconds and say I wish you would go away 4 times and when you wake up the next day it will be gone!!!