Export and Import user access using Sitecore PowerShell Extensions

ExportAccess.ps1

# Use this report to export current access
$users = Get-User -Filter * | Where-Object { $_.Roles.Count -gt 0 }

$records = [System.Collections.ArrayList]@()
foreach($user in $users) {
    $record = [PSCustomObject]@{
        "Username" = $user.Name
        "Roles" = ($user.Roles | Select-Object -ExpandProperty Name) -join ","
    }
    $records.Add($record) > $null
}

$records | Show-ListView

ImportAccess.ps1

# Use this to import the report
$path = Receive-File -Path $SitecoreTempFolder
if ((Test-Path -Path $path)) {
    $records = Import-Csv -Path $path
    foreach($record in $records) {
        Write-Host "Adding user $($record.Username)"
        if((Get-User -Id $record.Username -ErrorAction 0)) {
            $roles = $record.Roles -split ","
            foreach($role in $roles) {
                Write-Host " - $($role)"
                Add-RoleMember -Id $role -Member $record.Username   
            }
        } else {
            Write-Host " - User has not logged in before"
        }
    }
}