MK3 Update step-by-step

[sanchower]

Hi guys.
Can somebody guide me to update Navi Software on MK3? I thought the update process is very difficult and a lot of updates finishes with errors and crash the MK3. So I need to understand how to update MK3 and not to get the errors.
1. Can I use the BMW V31 Navigation Software.iso downloaded from this site or it is only for MK4? Or its include all MK updates?
2. Can I hack the splash-screen with navtweak-software or the MK3-hacking is different?
3. Can I overwrite the original file in "Voices/0506" with my lang or it will damage the iso-image?

Can someone write a step-by-step guide for updating MK3?
Thanks. Sorry for my bad English