How can I switch back to Legacy 6 from Legacy 7?

If you don't wish to upgrade and wish to return to Legacy v6 Deluxe, here are the steps to do that:

The first thing you need to do is create a GEDCOM file in Legacy v7 (File > Export to... GEDCOM file), unless you created a backup before installing Legacy v7.

Then with the Family File open, go to File > Delete Family File to delete that file.  Legacy v6 will not open the Family File once it's been opened in Legacy v7 so we need to get rid of that file and have the GEDCOM or backup available to create a new file for v6.

Uninstall Legacy 7.0. This will not delete any of your family files, pictures or other data.  It will only remove Legacy 7.0.
After you uninstall Legacy, with Windows Explorer look in the C:\Legacy folder or whichever folder you had Legacy installed in.  Within this folder you will find several files remaining that you will need to delete.

Carefully delete the following files with the file extension of:

.usr   (defined as "USR File")
.exe  (defined as "Application")
.ocx  (defined as "ActiveX Control")
Legacy.exe.local (defined as "LOCAL file")

DO NOT delete any of the folders like the Data folder, Picture Folder or Web Folder as these folders hold your data and you don't want to accidentally delete your family file or pictures.   Don't delete any reports you may have saved to the main Legacy folder.  All the other files should be deleted.

You'll need to reset your preferences after you reinstall.

Use this link and download and install the most recent build of Legacy 6.0.

The password required to install is on the website with the download information.
Start Legacy 6.0 and click on Help, Unlock Deluxe Edition and enter your version 6.0 Deluxe Edition Customer Number.

Either import the GEDCOM file into Legacy v6 or restore the backup.