The new league client

How do i get the old league client back, because of the old league client its very slow on my computer and so i didn't realize i was picking and got a 5 minute wait timer. After that i realized that when i locked it, and opened up my masteries page i could not edit my masteries, and was left with a blank one, and so i dodged. Now i have an even longer wait limit. Also with this league client having such a matching color scheme and blending everything together, it is very hard to notice and find things and navigate through it.