Obtain summary and other information on Mazinger Z: Mycenae no Densetsu no Maki. Any translated info about this is very scarce and rare given the limited copies there were. Whoever finds it get bragging right for life.
Speak and find any connections with fans across the web, it can really help the wiki grow and get good international support.
Help build pages for the franchise's merchandise. This especially includes Chogokin.
If you don't want to do any of that, then just find some stuff that looks like it should be changed.