I was one of the validators that was late and subsequently jailed, so if any other validators are still stuck on how to resolve it (or for future reference), here was the process:
Step 1. Update to latest v0.34.6 build with the security patch
Step 2. Remove current blockchain state. gaiad unsafe-reset-all to wipe .gaiad/data folder.
Step 3. Download snapshot of blockchain tar file into the data directory. https://cosmos-data-backup.s3.ap-northeast-2.amazonaws.com/data_hub2_backup_before_unbonding_hardfork.tar
Step 4. Run tar -xvf on the snapshot and move into the data directory.
Step 5. Within the config file, add updated peers from this list: https://github.com/Ethermat/cosmos-topology/blob/master/peers_0.31.5.txt
Step 5. Start and sync gaiad. Once synced to unjail validator run: gaiacli tx slashing unjail