Once they comment or post on your muni, the mod options next to their comments include one to make them a mod.
Be careful, currently removing a mod is a bit bugged.
Welcome to the official Lemmy.world Support communitiy! Post your issues or questions about Lemmy.world here.
This community is for issues related to the Lemmy World instance only. For Lemmy software requests or bug reports, please go to the Lemmy github page.
This community is subject to the rules defined here for lemmy.world.
Support tickets can be created by sending an email to info@mastodon.world
Once they comment or post on your muni, the mod options next to their comments include one to make them a mod.
Be careful, currently removing a mod is a bit bugged.