Want to swap who's a farmhand and who's the host? This handy tool performs the changes described in this guide for you: www.reddit.com/r/StardewValley/comments/8i5z1j/guide_how_to_change_hosts_of_a_multiplayer_save
Always keep back-ups! Modifying save files can break your game or be incompatible with updates. Use at your own risk.
See https://stardewvalleywiki.com/Saves for where to find your save file. Once it's parsed, option buttons will appear. (It can take a minute.)
Results will appear here.
Known issues:
Issues fixed (9/23/2018):
Issues fixed (7/31/2018):