In response to the original poster, there are two ways to do it.
The first way is to use the Save/Restore app that is linked everywhere and works very well for what it does. This will save all your texts and call history into an HTML file to view on a computer or on your phone. It will NOT restore your texts and call history on the phone, though.
The second way is messy but works to do what you want. It requires saving your old palmdatabase.db3 file (along with backing up the USB drive and doing a Save/Restore), doctoring your phone or just Erase Apps and Data, saving the NEW palmdatabase.db3, opening the new database and writing down all the relevant IDs, opening the old database and overwriting the IDs with the new IDs, then putting the updated old database onto your phone.
Like I said: it's messy. It's also somewhat complicated and doesn't have 100% success rate. Rwhitby is the pro at this stuff and has said over and over that he doesn't recommend trying that method to back up. Hopefully Rcmarvin's investigation into the new db8 structure ends up working so we can move our texts from the Pre- to the Pre3.
If you really insist on doing the database edits, let me know and I'll find the forum post where the instructions are detailed.