Forums account deletion

Hello, I've been trying to clean up some accounts on services I no longer use
I've been poking around with the settings but it doesn't seem like I can delete this account, or even manually delete any of my posts. There's this account and another I want deleted

Is there any procedure for this? Or do I just email support?
I don't just want to lose access to the account, I want my posts and comments deleted too
Thanks