The guild FAQ suggests that the guild owner has to initiate the transfer of the ownership themselves.
I don't think there is a way to transfer the ownership without the consent of the owner.
https://forums.d2jsp.org/info.php?p=5Quote
Q: Can I transfer Guild Ownership to someone else?
A: Yes. If you are the guild owner and wish to resign and transfer your guild to someone else, I will do a transfer for you for 1000fg. Contact a mediator for more information and assistance, as this process is not automated. Please note that IRC is not included in guild transfers.