How to change block textures for Minecraft on Mac?

I have a Mac computer and recently got mine craft on it, I want to edit what the blocks look like in my game but I can't find how, I'm not trying to add a texture pack, I just want to change the look of the blocks myself. I've googled ways but can't find any results. In my minecraft folder there's the following:
Assets
Config
launcher_profiles.json
launcher.jar
launcher.pack.lzma
libraries
logs
mods
options.txt
resourcepacks
saves
versions

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Download winrar for mac, install it, open the "versions" folder, open the folder named "1.7.10" or whatever the folder in there's named, there will be a.jar file in there. Open it using winrar. Once opened there will be a folder called "assets" open it then open the folder "minecraft" in there there's another folder called "textures". Right click it then pick "Extract to the specified folder then choose desktop and click "ok". Do not close winrar. Once finished open the textures folder where ever you put it then open the "blocks" folder. Edit however you want. Drag the "textures" folder, from where ever you put it, to winrar, click "ok". Close winrar and play minecraft