Minecraft on mac help please!?

[Grant]

I am trying to install some mods on my mac for minecraft but i can't delete the meta-inf (i think thats what its called) when i open the minecraft jar i get a folder named minecraft and then when i open it and delete the meta-inf it is gone but then when i open the jar again its there. i have also tried just deleting the things that say mojang in the meta_inf but it doesnt allow me to install the custom npc mod. i want this mod so bad and i tried installing it without deleting the meta inf but it still didnt work. can anyone please please please give me a step by step on how to do this on mac using archive utility? (i dont have winrar and im not getting it) and please dont send me a link ive gone through a billion of those

[Bob]

Here is all the mac and apple help in one place... Hello, Ask Apple here for free 1-800-MY-Apple ,and check out the sites for more informaton http://www.apple.com/support/ and
https://discussions.apple.com/thread/246...0&tstart=0
http://www.facebook.com/pages/TheAppleGossip/...
http://www.apple.com/macosx/recovery/
http://9to5mac.com/
http://appleid.apple.com
http://www.apple.com/support/mac/facetime/
http://www.ifixit.com/iPad-Parts and Mac parts
http://www.apple.com/iphone/built-in-app...phone.html
Hey, I enjoyed your question, I have worked as a technician most of my life, I
hope I have helped you...
Good luck...

CompTIA A+ Certified Computer Professional