Change the leader

Anas_wick99

If the leader is offline for like +7d an officer can spend units or gold to replace him

Iamnike

Just leave the alliance bro

SummonerNR

After 28 days, automatic process then (or can contact Support after that 28 days of inactivity).

https://help.kabamsupport.com/hc/en-us/articles/360052118332-Alliance-Leadership-Change-Requests