Go to Feedthebeast/blastoff/minecraft/mod folder, Delete the adventurebackpack.jar file and replace it with the one you downloaded."Update Adventure backpack to V74B
http://www.minecraftforum.net/forum...adventure-backpack-mod-beta-0-7-4b-updated-31"
Sorry for the noob question: How? There is a download button, if/when I get that file what do I do with it?