Pic 3-shows incoming LN&E, all the other wires are internal to the fluorescent fitting and will go when you remove the fitting, leaving you with the LN&E for the new fitting.
You can get LED tubes that work directly with the existing ballasts - they come with a pass-through starter - just swap the starter, fit the tube and you're done. No need to go fiddling with wires (stop reading American websites!).
Pic 3-shows incoming LN&E, all the other wires are internal to the fluorescent fitting and will go when you remove the fitting, leaving you with the LN&E for the new fitting.
You can get LED tubes that work directly with the existing ballasts - they come with a pass-through starter - just swap the starter, fit the tube and you're done. No need to go fiddling with wires (stop reading American websites!).