I have a Minecraft Texture pack installed which was partially successful and now I want to have the normal Minecraft textures again how does it work?
By selecting the default pack under Resource Packs in the menu.
Under Resources on the icon of the TP, click on the left arrow.
On the left are all your uncharged TPs and those on the right are all used.
Normally Options → Resource Packs and then click on the left arrow on your texture pack