Migrates scheduled tasks created by specified users and scripts from old server to new server. Also replaces all references to old server in ps1 files with new server name and disables those tasks on retired server.

Migrate-ScheduledTasks.psm1

# PowerShell function: Move scheduled tasks from old server to new server
# Author: thegooddoctorgonzo 20180424 
Function Migrate-ScheduledTasks {
<#  
    .SYNOPSIS  
        Migrates scheduled tasks created by specified users and scripts from old server to new server. Also replaces all references to old server in ps1 files with new server name
    .DESCRIPTION  
        Migrates scheduled tasks created by specified users and scripts from old server to new server. Also replaces all references to old server in ps1 files with new server name
    .EXAMPLE  
        Move-ScheduledTasks -OldServer Serv1 -NewServer Serv2 -Authors domain\user -MoveScripts   
    .PARAMETER OldServer 
        Name of source server  
    .PARAMETER NewServer 
        Name of destination server
    .PARAMETER Authors 
        Author of Scheduled Tasks to be moved. Accepts multiple inputs seperated by comma
    .PARAMETER MoveScripts 
        Switch to move scripts in c:\Scripts to same folder on new server
    .OUTPUT  
        None  
    .NOTES  
        Written by Steve Landry 20180424. 
  
#>
[cmdletbinding()]

Param (
#Name of source server
[Parameter(Mandatory=$true)]
[string]$OldServer,
#Name of destination server
[Parameter(Mandatory=$true)] 
[string]$NewServer ,
#Author of Scheduled Tasks to be moved. Accepts multiple inputs seperated by comma
[Parameter(Mandatory=$true)]
[string[]]$Authors ,
#Switch to move scripts in c:\Scripts to same folder on new server
[Parameter()]
[switch]$MoveScripts ,
#Location of folder on OldServer containing scripts
[Parameter()]
[string]$Repository ,
#Switch to leave tasks enabled on old, disabled on new, will still transfer task XMLs and scripts if MoveScripts switch enabled
[Parameter()]
[switch]$StageOnly
   ) 

Process {
#create folder for exported tasks XML
if(!(Test-Path -Path ("\\" + $OldServer + "\c$\ExportedTasks")))
{
    Invoke-Command -ComputerName $OldServer -ScriptBlock {New-Item -Path c:\ExportedTasks -ItemType Directory -Verbose}
}
#export scheduled task XML
Invoke-Command -ComputerName $OldServer -ScriptBlock {$Auth = $args;Get-ScheduledTask -TaskPath '\' | Where-Object -FilterScript {$_.State -ne 'Disabled' -and $Auth -contains $_.Author} | foreach{ Export-ScheduledTask -TaskName $_.TaskName -TaskPath $_.TaskPath | Out-File -FilePath (Join-Path "C:\ExportedTasks\" "$($_.TaskName).xml") -Force} } -ArgumentList $Authors -Verbose

#copy XML folder to new server and rename
Copy-Item -Path (Join-Path "\\" "$($OldServer.ToString())\c$\ExportedTasks") -Destination (Join-Path "\\" "$($NewServer.ToString())\c$\") -Recurse -Verbose
Rename-Item -Path (Join-Path "\\" "$($NewServer.ToString())\c$\ExportedTasks") -NewName ImportedTasks -Verbose

#movescripts switch present - copy scripts old to new
if($MoveScripts)
{
     Copy-Item -Path ("\\" + $OldServer + "\" + $Repository.Replace(':','$')) -Destination ("\\" + $NewServer + "\C$\" ) -Force -Recurse -Verbose
}

#collect individual .ps1 files
$files = Get-ChildItem ("\\" + $NewServer + "\" + $Repository.Replace(':','$')) -Include "*.ps*" -Recurse
#and replace references to old server with new server
foreach($file in $files)
{
    (Get-Content -Path $file.FullName) -replace $oldSErver.ToString(), $NewServer.ToString() | Set-Content $file.FullName -Verbose
}
#import tasks to new server
Invoke-Command -ComputerName $NewServer -ScriptBlock {$XMLs = Get-ChildItem -Path "C:\ImportedTasks\"; foreach($XML in $XMLs){Register-ScheduledTask -Xml (Get-Content $XML.FullName | Out-String) -TaskName $XML.Name -User "DOMAIN\USER" -Password "P@ssw0rd" -Force}} -Verbose

if(!($StageOnly))
{
    #disable tasks on old server
    Invoke-Command -ComputerName $OldServer -ScriptBlock {$Auth = $args;Get-ScheduledTask -TaskPath '\' | Where-Object -FilterScript {$_.State -ne 'Disabled' -and $Auth -contains $_.Author} | Disable-ScheduledTask  } -ArgumentList $Authors -Verbose
}
else
{
    Invoke-Command -ComputerName $NewServer -ScriptBlock {$Auth = $args;Get-ScheduledTask -TaskPath '\' | Where-Object -FilterScript {$_.State -ne 'Disabled' -and $Auth -contains $_.Author} | Disable-ScheduledTask  } -ArgumentList $Authors -Verbose
}

}
}

Added functionality:
Parameter -Repository: Designate location of folder containing scripts on OldServer
Parameter -StageOnly: Switch. Will copy scripts and task XMLs if designated, but will leave tasks on OldServer enabled and disable tasks on NewServer

Fixes:
$files variable was pointed to incorrect directory, now points to $Repository

Fixes: Fixed Copy-Item destination path

Fixes: Fixed Get-ChildItem line to collect all/only .ps files

Fixes: Fixed Get-Content - substituted .Replace with -replace to ignore letter case