Firstly get Too many Items.
Secondly get mcpatcher.
Once you have gotten these two things, open up mcpatcher and it should start to initialize minecraft.jar.
Once that is done, at the top of mcpatcher, there is a button called "mods", click on that.
there should be a tab popping out, click on "add"
now there should be a file select, choose the too many items ZIP. It is impportant that it is a ZIP file.
After that click patch near the bottom of mcpatcher.
Once patched, you're done! you can close mcpatcher.
Start up Minecraft and have fun!

-spiefie99