You can't 'cherry pick' just one of the 8-10 Lacerte files to send.  

Either:

1) Do a backup (using the Lacerte BackUp function/Ctrl B) to a thumb drive & provide that to the new preparer

2) Highlight the client > Upper Menu Bar >  Send via email >  this will create a file that you can then email to someone (if you use Outlook), or copy the file created to a location you can access.  Then draft an email, find that file you just created and attach.