How do you wipe hard drives already in use, safely?

[solitonmedic]

Hi there, I made a mistake during installation and I don't have the means to physically access my server.

Is there a way to wipe the following disks (circled in red) so it can be used for other means? I only need "/dev/sda" unchanged.

 

[leesteken]

What is the output of zpool status and proxmox-boot-tool status? We need to know how the ZFS partitions are used.