I solved the question after a bit of help from Sergey Alexandrovich Kryukov.
He said that JAR Files are the same as ZIP so I used this code to extract my JAR.
Dim cur As String = (Environment.CurrentDirectory)
Dim MC_JAR As String = install_path.Text & "\bin\minecraft.jar"
Dim TEMP_FOLDER As String = cur & "\Install_Data\temp\minecraft.zip"
Dim sc_1 As New Shell32.Shell()
Dim output_1 As Shell32.Folder = sc_1.NameSpace(cur & "\Install_Data\temp")
Dim input_1 As Shell32.Folder = sc_1.NameSpace(cur & "\Install_Data\temp\minecraft.zip")
System.IO.File.Delete(cur & "\Install_Data\temp\minecraft.zip")
This code copys the jar to a temp folder and it will copy it as a zip file then it will extract all data from the zip and it will remove the zip file and give the user a message that it is done.