Help for ROLE SET:

ROLE SET allows you to modify the flags of a role that
already exists. All users in the given role will receive
the effects of the changes. Multiple flags should be
separated by a space and have the modifier (+ or -) before
each flag.

Syntax: ROLE <#channel> SET <role> <flags>

Examples:
    /msg &nick& ROLE #atheme SET channel-ops +acl-change +set +recover
    /msg &nick& ROLE #atheme SET helpers +invite
    /msg &nick& ROLE #foo SET helpers -topic -invite
