Use XSE(the official link is broken, google it) to edit text, it's safer anyway. Also use Free Space Finder to find out where you should put the text/script.
It seems like you're trying to replace text rather than make new ones, o delete the text, then hit Ctrl + T to get the text editor. Click Convert -> Insert in the text editor. Remember how many characters are there, and find that many bytes in Free Space Finder. You'll get an offset, and write that down in notepad or whatever. Above the string of text you edited, there will be #org 0x8(other numbers). Write the offset you got in Free Space Finder over those other numbers, then compile and decompile.
Remember to make back-ups!