If you have forge, place the .zip file in the mods folder. No need to delete meta inf for forge. However, I dont really know what your asking here. Please give me a more in-depth problem and I will try my best to understand what ur asking. Thanks - Developing_
1 More thing, I don't understand if your giving me a tutorial on how to install pixelmon, but if it is a tutorial, please post it in the Blogs section. - Thanks again, Developing_
More information on installing mods with forge:
In your appdata search for "mods" folder forge should have installed. And place the downloaded .zip file in there, Forge should automatically unpack it when you launch the FORGE profile. If you are installing mods that require forge, without forge. This could happen. But I dont know. But with a mod that REQUIRES FORGE please do not make a new profile just place the downloaded .zip file in your mods folder.
-Developing_