Can’t write to

I am a novice and don’t even know html but am trying to learn to modify a WordPress template. I purchased “WordPress for Dummies” and am following Lisa’s instructions. However, Lisa gives instructions on using the wp-admin presentation theme editor to modify/update theme files. The following message displays at the bottom of my theme editor window:

“If this file were writable, you could write to it.“

I searched the www.remarpro.com support site and found that I’d have to alter my chmod. In the wordpress documention you are directed to:

Using the Command Line

If you have shell/SSH access to your hosting account, you can use chmod to change file permissions. Before you start using chmod it would be recommended to read some tutorial like this and also the manual page to make sure you understand better what you can make with it.

You can make all the files in your wp-content directory writable in two steps:

1. Go to your WordPress main directory, with a command like cd wordpress/
2. Enter chmod -R 777 wp-content

My question is, where do I do this? In filezilla? I don’t know how to get to the WordPress main directory, nor do I know where I’d type the command cd wordpress/ or chmod -R 777 wp-content.

I just don’t know where to input these keystrokes.