Hello, I want to translate the in-app tutorial videos to Spanish from Spain. I'm comfortable with video editing/recording, and my partner is a voice actress so she can do all the voice-over, and I can do the editing. I would love to know who is the person that I would need to talk to make it happen. I will need the original videos in video format, if there is any music in the background of the original video that audio file, and if there is any spec that I must follow. My plan is to translate the tutorial saying the same things and record the parts where the interface is shown to show that in Spanish.

Awesome! I'm also from Spain and I've always wanted this videos in Spanish.
You should contact the translation team over email at this address: translate@scratch.mit.edu

Thanks! I'll contact them!