So you have a lot of IIS Servers to manage and the logs are taking up space? No worries, use/modify the following script and schedule a daily job to delete the older log files automatically every day. This script assumes that you have all the log files in the same location.

#Write down all the server names here. I had only two servers WFE1wSQL and AS1
$Servers = "WFE1wSQL", "AS1"                
#This script assumes that you have the log files in the same folder on all servers.
$source = "C:\WINDOWS\system32\LogFiles"    
$date = Get-Date
#Number of days = 30 would imply deleting all the files older than 30 days.
$retention = $date.AddDays(-30)

foreach ($server in $servers)
{
    try
    {
        Write-host "Deleting the old IIS log files from" $server
        #Make a path like \\ServerName\C$\Windows\System32\Logfiles
        $remotefolder = "\\" + $server + "\" + $source.Replace(":", "$")
        #Use a filter to filter all log files which are older than Retention period
        $folder = Get-Childitem -Path $remotefolder -recurse -filter "ex*.log" | where {$_.CreationTime -le $retention}
        if($folder.Count -gt 0){ $folder | remove-item }
        else {Write-host -ForegroundColor Red "No files found"}
    }
    catch
    {
        $err= $_.Exception;
        Write-Host -ForegroundColor Red $err.Message
    }
}
 

Hope this helps,
Rahul