Powershell change RTF Document and save as RTF Document
Use the Get-Content cmdlet to load the file, do your replacements and finally write it back using the Set-Content cmdlet.
Example:
$filepath = 'Your_file_Path'$content = Get-Content $filepath -raw$content = $content -replace 'ReplaceMe', 'IReplacedYou'$content = $content -replace 'ReplaceMe2', 'IReplacedYou2'$content | Set-Content $filepath