I do it manually via dump and restore using sqlite3...
- Stop weewx
- Make a copy of your old and new db and work off those copies
- cp weewx.sdb /var/tmp/weewx.new.sdb
- cp your_old_weewx.sdb /var/tmp/weewx.old.sdb
- cd /var/tmp
- Dump your old database's archive table to a file
- echo ".dump archive" | sqlite3 weewx.old.sdb > old.dump.txt
- Restore that into your new database
- "cat old.dump.txt | sqlite3 weewx.new.sdb"
- (and ignore the 'table already exists' warning)
- Rebuild your daily summaries
- rename your production weewx.sdb file to something else
- copy the weewx.new.sdb built above into place as weewx.sdb in the directory weewx expects it in
- sudo wee_database --rebuild-daily
- Start weewx
ALWAYS save your original files just in case....never work off your originals.....
The stuff above is loosely tested but should work ok.
Again, ALWAYS save your original files just in case something goes sideways.