Handling snapshots (creating, deleting, restoring) is rather intuitive when you already have some experience with PowerCLI. As a reference, here are some one-liners. As always with Powershell, there's more than one way to achieve a goal... The examples used here assume a VM named "SRV01". Adjust as needed.

Create a snapshot:

Get-VM SRV01 | New-Snapshot -Name "My snapshot"

Remove all snapshots (disabling confirmation request in the process):

Get-VM SRV01 | Get-Snapshot | Remove-Snapshot -Confirm:$false

To handle a specific snapshot, you could do something like this:

$vm = Get-VM SRV01
$snap = Get-Snapshot -VM $vm -Name "My snapshot"
# do something with the snapshot in variable $snap

Then, to delete that particular snapshot:

Remove-Snapshot -Snapshot $snap

To revert to that particular snapshot:

Set-VM -VM $vm -Snapshot $snap