Anyone know how to do a upgrading from 1.23 to 1.28.3 (lates

Anyone know how to do a upgrading from 1.23 to 1.28.3 (lates
Still using the old version. But now the latest is 1.28.3. Don't want to re-do everything. Any shortcut I can use.
Thanks in advance.
Still using the old version. But now the latest is 1.28.3. Don't want to re-do everything. Any shortcut I can use.
Thanks in advance.