you can either force update your minecraft via the login page or you can delete the entire bin folder
right click and click "move to trash" or "delete"
To install Multiverse, Open your Mcmyadmin file, find the Plugin file (should be in the "minecraft" file) paste the multiverse .jar files in the plugin file. Thats it, Your done.
premium: get the 1.0.0 Minecraft jar here modsforminecraft.com/ and delete the Minecraft jar that you have and put the 1.0.0 jar in
If you are using window's, then use the Run program, and type in %appdata% and then run that, and it will bring you to a file containing the .minecraft folder.
find a .minecraft folder with zombiecraft already installed then replace it with your normal .minecraft then run the .jar file but DONT force update (minecraft 1.1)
You can easily recover your fresh minecraft.jar by opening the launcher, clicking options and selecting Force Update. This will force the game to update your .jar to the current version, wiping all extra files including mods. Also, when using mods, be sure to delete the META-INF file inside the .jar file.
If you search minecraft alpha jar file on google you can download the jar file and replace your current one. Also you can go to minecraft.net and play the free browser version.
Download it off the minecraft forums. Then drag everything in the file into the minecraft jar on winrar, or 7zip.
right click and click "move to trash" or "delete"
To install Multiverse, Open your Mcmyadmin file, find the Plugin file (should be in the "minecraft" file) paste the multiverse .jar files in the plugin file. Thats it, Your done.
Download the .jar file and then replace that one with the one in your .minecraft directory at \C:\*User*\AppData\Roaming\.minecraft\bin
premium: get the 1.0.0 Minecraft jar here modsforminecraft.com/ and delete the Minecraft jar that you have and put the 1.0.0 jar in
You need to install an older .jar file.
If you are using window's, then use the Run program, and type in %appdata% and then run that, and it will bring you to a file containing the .minecraft folder.
Try it again. Delete the .jar, reopen Minecraft, it'll redownload a vanilla .jar. Then do the exact same thing.
There is one way, and one way only. You need to find a download containing either a .jar file or the full on .minecraft file of the desired version. Go to %appdata% (When you type it, it will take you to the appdata folder) Then either Delete the current .minecraft or go deeper and replace the .jar with the one you want. Remember to back up newer maps for they can be corrupted with an older minecraft.
find a .minecraft folder with zombiecraft already installed then replace it with your normal .minecraft then run the .jar file but DONT force update (minecraft 1.1)