All that you will need is: scissors, a plastic water bottle, and I recommend a screwdriver.
Step 2: Removing That White Thing...
This is why we need a screw driver. Use the screw driver to pry that thing off.
Step 3: The Holder
Most bottles have a funnel-shaped top. That will be your holder. Cut it off and the end of the funnel shape (see picture). Just tear at it with the scissors until you have a slit and keep cutting from that slit.
Step 4: Even it out
Now even out the cut you just made. This step is self-explanatory, that means no blurry pictures.
Step 5: Wash
Wash your almost-finished product, also self-explanatory.
Step 6: Use
Insert egg..... not much else to say.
This was my first instructable. Please let me know what I should do better in future 'ibles.