A simple Find & Replace script for changing names of things withing Linked Service, Dataset, or Pipeline files.

Find_and_Replace.ps1

<#  Search for something inside an ADF file and replace it. #>
$Datasets = dir 'C:\temp\MDD-ADF-Test-Repo\dataset' -Recurse
foreach($Dataset in $Datasets.Where({$_.Mode -ne 'd----'})){
    $Dataset.Name

    if((Get-Content $Dataset.FullName | foreach{ $_ -match 'AzureSqlDatabase1' }) -eq $true ){"Fix it"
        (Get-Content $Dataset.FullName).Replace('Azure_SqlDatabase1', 'MDD_SampleSQL_LS') | Set-Content -Path $Dataset.FullName }
    else{"Nothing to do"}
}

<#  This isn't limited to just Datasets.  you can go up one level and do the replace on every directory if you include the -Recurse parameter.    #>