How to make hack saves on 4.0

I was think about making a exploit but I'm a beginner.

I was thinking about doing the exploit on MKWii (Mario Kart Wii)

Here a list i need help with.

1.How does the game read the time trials.

2. Can someone tell a tutorial how extract/modify save files.
(One that a beginner could understand. The one that are in bin format)

3. How to make a code that can load the boot.dol

4.Putting it back to a bin file that the wii/game can read

P.S It would be really be nice if someone can give us a modify Mario Kart Wii save that can run the homebrew installer. I have wii firmware 4.0.

You can edit saves in a HEX editor i believe
but im not sure it would work due to the fact that most Wi-Fi games dont let you copy other save games