Dude newbie to newbie let me break it down for you brother....
- As a newbie, rule 1 o 1.. YOU NEVER EVER screw with the original... EVER!!!! are we clear
Your going to need to do this in 2 or 3 steps (programs)
Step 1. Take content off your website.. to PC as a second copy to work on/modify
Step 2. Modify content in Editor
Step 3. Test content before replacing web originals...
Step 1. You need to use an FTP program like Filezilla to do this.. by far the most popular/free ftp
Step 2. You already understand!
Step 3. PHP testing is a little tricky, it only works online.. to get around that you make a mini server on your PC
with a program called XAMPP by Apache.. pick the right one for your PC... Will take some time/newbie stuffing around....
Download links: FileZilla and XAMPP
YouTube: both + Tutorials for endless demos
Sorry mate not as easy as you hoped
Closing note: Do not mess with the online original!.. Your code editor "Aptana" may make code corrections it thinks are errors or inefficient, you dont notice.. It doesnt work.. what will you do then??... You beat he'll make you pay double for the clean up while laughing in your face!!!!
note: Ive assumed you"re using some form of Microsoft Windows? and to the old crew.. when the hell did XAMPP get to 120mb??? last play was 1.7 at 60mb?