===MULTIVERSION===

Step 1: Copy files in "minecraftdir" to your Minecraft directory (usually .minecraft)
Step 2: Copy Beta 1.7.3 jar into your (minecraftdir)/versions/multiversion folder and rename it multiversion.jar
Step 3: Copy files in "jar" into multiversion.jar using 7-Zip, WinRar or your preferred program and delete META-INF
Step 4: Start Multiversion in launcher