First of all, you need to be certain you want to upgrade Vault. Starting from
v5, all network information could be downloaded through QR codes and upgrades are needed only to add new software features.
Make sure your keys are backed up - you should have all seed phrases and derivations recorded somewhere. Once you proceed to the next step, there is no way to recover lost information.
Make sure to back up all keys for all networks you use. Ideally you should already have some kind of backup, make sure it is up to date.
Once you are certain that you have backed up everything, open settings, select
Wipe all data button and confirm your action. All data in the Vault will be factory reset; congratulations!
When the Vault is removed, wipe the phone to factory state. This is good time to install newer version of operating system if you like. Make sure your system is genuine by all means provided by OS vendor.
Before installing the Vault, you need to set up the phone. It is essential that you enable sufficient authentication method; your secret seeds in Vault are as safe as the phone is. Seed secrets are protected with hardware encryption based on vendor authentication protocol. Other than that, you might want to select dark mode (Vault remains dark for historic reasons)
Download signed application through application store or from github. Make sure the signature is valid! Install the app. Do not start the app just yet!
Before starting the Vault, you should make sure that network is disabled. Many operating systems allow only partial network monitoring; although there are network detection features in Vault, they are limited and only have informational function. User is responsible for maintaining airgapped state! The simplest way to disable connectivity is setting the phone in airplane mode. Advanced users might want to use physical methods to further protect the phone from connections. Perform all preparations before starting the Vault app!
Start the app. Read and accept information provided on launch. Congratulations! The app is ready to use now, however it does not have any keys and only few basic built-in networks. Proceed with setting up keys and adding new networks.