How to change Rank Icon of a caster (ex. Priest or Shaman)?

[WazzapMama]

SO my brother made his own custom unit Caster (originally based from a priest), although successful, he's having a hard time changing the Ranking Icon. Can someone please help us how to change a custom rank icon? thanks for the help in advance.

 

[Chaosium]

It's this line in the unit editor, the icon is the same format as the weapon/armor upgrades

 

[WazzapMama]

It's this line in the unit editor, the icon is the same format as the weapon/armor upgrades

View attachment 426632

Thank you for the reply.
yes, he finally got it. Thank you for the help.