For anyone else stumbling on this thread, or anyone who wants to do the upgrade on a system with very little spare disk space (e.g., a VPS), the Elysium Pool bootstrap can be used to switch to the v2 update as follows.
- Upgrade Chia to v1.3.1. Stop the Chia program.
- Follow the instructions on the Elysium Pool bootstrap page to download the v2 database torrent and extract it.
- Edit the .chia/mainnet/config/config.yaml file to change the line that says
database_path: db/blockchain_v1_CHALLENGE.sqlite
todatabase_path: db/blockchain_v2_CHALLENGE.sqlite
(i.e., change v1 to v2). - Start the Chia program as usual.