Two of the easter eggs are already spoiled in the screenshots and are exactly or near the place where the screenshot was taken. In one of them you need to stop and press the brakes and in the other one you need to be really fast in order not to fall. I can also help you with the third one. You need to jump as high as possible and in order to land as high as possible.
The other 3 are a bit harder to find. You need to try to do new stuff and be in places you're not supposed to be.