What are the steps to terminate the EBS volume?

we can select the volume which we required to delete/terminate, if the volume attached to a running instance then select Volume => actions => detach volume => delete volume,

Also if the the option delete on termination is enabled for a instance then this volume will be deleted once the instance terminated

How can we expand the size of the volume?

we can expand the EBS volume by selecting the volume => actions => modify volume => increase the volume => modify this way we can expand the volume.

What are the steps to terminate the EBS volume?

How can we expand the size of the volume?

Can I reduce EBS volume size?

No, you can't reduce the EBS volume, We can create a small volume and we can migrate the data to that volume.