Hi 2010BEBES,
Here are the answers for your two questions:
1. Upgrading Little Reader while saving personalized content:Before proceeding with the upgrade, please make sure that you save a backup copy of all your LR lessons (especially the ones you created or downloaded). To ensure that you save all your LR content, I highly recommend that you use LR's Backup function, because this way you can save all your LR lessons and media files.
How to backup your entire Little Reader library
http://support.brillkids.com/entries/20586247-how-to-back-up-your-entire-little-reader-library** Please save your backup in a different location (like your Desktop or My Documents, but not inside any BrillKids folder)
Once you're done with your backup, you may go ahead and follow the upgrade prompt you see when you open Little Reader. Note that the upgrade process will involve 1) downloading the upgrade installer, and 2) running the installer. This may take some time depending on your Internet connection.
If you encounter any problems or errors while upgrading, try cancelling or stopping the process, and then just download the software installer from your BrillKids Account and use that one instead.
When you're done upgrading LR, you can simply restore your backup file by double-clicking on it (or open LR and go to Tools > Backup/Restore, then click Restore and open your file).
2. Applying customized content to another LR installation:Since you've already saved a backup of your LR content (from #1 above), all you need to do now is to copy your backup file and transfer it to your other computer (where your 2nd LR installation is) and then restore your backup file there.
I hope this helps!