Just so I don´´´´´´´t use this wrong. When I use the R4 token mechs, would this be the correct way of doing it?

1) Kimogila with R4 agromech and deadeye shoots out a Harpoon missile using it´s focus, can I then use the target lock to modify the attack?

2) Kimogila with Overclocked R4 and deadeye shoots out a harpoon missile using its focus, can I then use the new focus to modify the attack?

Harpoon Missiles don't require you to spend the token to fire them, so in each case yes, but not for the reason you expect. They're not the only ordnance that doesn't, it pays to read missiles carefully. Only spend the token if it tells you to.

1: For Harpoons specifically, you can fire them using Deadeye, then later in the attack spend the focus, gain a target lock, and spend that too. But for an ordnance such as Assault Missiles, which DOES spend the token, R4 Agromech doesn't regain you the Target Lock, because the Defender hasn't been defined when you spend the token to make the attack.

2: See above for Harpoons, but this DOES work for ordnance that spends the token to fire - and any other reason you might spend a focus token, too. WHenever you spend a focus token, you can take a stress to get another.

But note that you can't spend a focus token to modify eyeballs to hits more than once per attack. So if you had multiple focus tokens (e.g. from Mindlink) and R4 Agromech, you couldn't for instance, roll eye blank blank, spend a focus token to convert the eye and gain a lock, spend the lock to reroll getting eye hit, and then spend the second focus to change that eye into a hit.

Thank you kindly, that was very clear.