HI,
I got a F700 a couple of weeks ago and have been messing with these hacks and has taken me a while to finally get results. I figure others may be having the same problems. Beside what is listed in the FAQ's I think that having this info in one place will help a lot.
The file to work with is zipped inside of data.zip\ui_pioneer\ 800_480\ui\ navigatemap_800_480.ui
It can be opened as a text file, you may need to change the last letters from .ui to .txt to get it open, then change it back when done with the hacks.
OK, now for the tricks. When you put the SD card in, at least on mine, after the initial copy I get a funky screwed up screen. Close it with the stylus or toothpick by pushing the x in the top right corner.
Next, at least on mine, I go to the bottom left start button and get to the control panel. Pick the "Stylus" icon and recalibrate the pointer position. By doing this (each time) I can use the edit buttons on the top of the windows screen, otherwise they do not react.
Close this window and open the "My Device" icon. Click on it, pick the memory card, and use the top edit button to copy the new Data file.
Close it, then go to the My Flash Drive, APL2/iGo and overwrite the data file with the paste key.
Close things up, pull out the SD memory, turn off the power, wait a few seconds, and your ready to roll 
Good Luck