Reply to How do I upgrade from 1.3 to 1.4?

Hey! I'm getting a used 1.3 firmware (the glitched one) VCI-100 today! I'd like to know how I can upgrade to 1.4... Do I need to buy the kit from this store?
If not, whats the procedure?
I'd appreciate a detailed answer since I don't really know a lot about this!
THANKS!