Multiple Volumes on a Sandisk External Drive

Hello.

I have a four-terabyte, Sandisk external hard drive that I use for backups of my 15-inch, M3 MacBook Air. When the M4 MacBook Air came out, I purchased one, and when I went to upload my data from the hard drive onto the new device, I was given the option to create a new volume because the device recognized that the backup was for a different device. I accepted, and, thus, the new volume was created. I ended up returning the M4 MacBook Air and would now like to remove the volume that was created. Is anyone able to help me with this? Thank you in advance.

Regards,

Mark