2.) type "%appdata% in the search bar
3.) open your .Minecraft folder
4.) right click "bin" then left click properties
5.) click the previous versions tab and select the bin folder with the date of before you updated.
6.) after you've found the version you want then hit the restore button at the middle right of the screen.
7.) now open your client and try not to update this time
i hope this helps
:D-Kenpachi