NB: the NEWcertificate.pfx certificate has already been successfully imported into IIS
iis - ssl certificate replace with powershell

Hello everybody.
I have this situation:
IIS with many sites with an SSL certificate associated with it (OLDcertificate.pfx)
I have this goal:
exchange the SSL certificate associated on multiple sites in IIS (with the new NEWcertificate.pfx)
I would kindly ask if anyone can help me locate the commands to do this task with powershell.
At the moment I am trying with these commands:
Get-WebBinding
Get-ChildItem -Path Cert: LocalMachine \ MY
$ OLDCertificateThumbprint = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
$ NEWCertificateThumbprint = "yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy"
Get-WebBinding | Where-Object {$ _. CertificateHash -eq $ OLDCertificateThumbprint} | ForEach-Object {Write-Host "Working on" $ _ $ _. RemoveSslCertificate () $ _. AddSslCertificate ($ NEWCertificateThumbprint, 'My')}
but it does not work.
thanks !