Download v0.1.11 (regardless of what they have installed as long as they want their wallets back and on the new gosuto)
Once done, they should not uninstall, but rather just download the new Gosuto (v0.0.4 or higher) and install it as usual (it should overwrite the previous one)
They should find their previous wallets in place - tested on windows and linux
Once done, they can use the password password to unlock their imported wallets.