PHP Help - CHMOD 0777

I'm trying to install IPB v2.0.4 online. When I go to the install page I get the following erros that need to be addressed before I can continue:

Warning! The following errors must be rectified before continuing!

·Cannot write to the file '../conf_global.php'. Please CHMOD to 0777.

·Cannot write to the file '../skin_cache/'. Please CHMOD to 0777.


I haven't the faintest idea how to do this. The only thing I know is that changing it to 0777 lets other things read and write to it...I think.

I don't know.

Can anyone help?