If you want to move snippets from one installation of SQL Prompt to another, or you're upgrading SQL Prompt, you'll need to copy the following folders:
%localappdata%\Red Gate\SQL Prompt 10\Snippets
%localappdata%\Red Gate\SQL Prompt 10\Styles
You'll also need to copy the following files:
%localappdata%\Red Gate\SQL Prompt 10\SavedTabs.db
If you're on a version after 10.13.0.31319 then this will be called SQLHistory.db instead.
You'll then need to save these folders/files in the same location on a new server. So the Snippets and styles folders can be copied into their respective folders on the new install.
For the SavedTabs.db/SQLHistory.db you'll need to copy it to the %localappdata%\Red Gate\SQL Prompt 10\ folder, replacing any existing files of the same name.
If you're copying an older SavedTabs.db file over to a SQL Prompt 10.13 or newer install, then the file will be updated to a SQLHistory.db file on startup of SSMS or VS.
If the new installation contains an existing .db file (SavedTabs or SQLHistory) that you'd like to keep, as well as the older file from the previous installation, then these files cannot be merged.