Updating Last Epoch to the latest version
We are currently working on a launcher which can perform in-place updates. For the moment you will need to download and install each build as it becomes available.
Character persistence
Characters currently do not carry over from one version to another. You can use Tab + D to open the Dev Mode panel and use that to speed-level characters if you wish.
Dev Mode will not be available when the game is released.
Stash persistence
The contents of your stash should typically be available after downloading a new version.
An exception to this is 0.4.9.7, where we reworked the stash so that softcore and hardcore characters have different stashes. This broke compatibility with previous saves.