Yeah the button for "hand feed override" I think it's called let's you adjust the speed and feed in 1% increments. Find what you like and the change the program.
To background edit, be on the main program page, where all you see is the currently active running program, type in the letter "O" followed by the program number and hit "F4" (I think, it's one of the function keys). Any edits you make get read after M30 or reset. I always hit reset to make sure. If you are in the "Current command" mode I think it's called, where it shows the program and position display, and hit f4 and shows it splits the screen between the program running and a program you can search through in the right side, but can't edit.