Currently, there isn't a migration tool to assist in switching from webweb to webweb2, as I suspect that I'm the only one who is using webweb. Luckily, switching isn't too difficult.
The main tables in webweb's database that you'll need to use are the Pages table and the Templates table. webweb does not have support for components. In addition, as mentioned in "How webweb2 works", draft pages have no direct equivalent, so you'll need to decide what to do with them.
To get started, you'll need to install a SQLite database viewer. The database file should be in the directory with the webweb executable, and it should be called app.db unless you configured a different connection string in your appsettings.json file.
The pages table has six columns that you'll need to pay attention to: page_name, page_html, page_css, page_js, page_head, and is_staging (which indicates whether the page is a draft).
For each row in the Pages table, you need to create a page in webweb2. Go to the menu and select "New item." Set the item type to "Page", and don't use any templates. The title of the page should be the value from page_name. In the Razor subtab, copy and paste the value from page_html, but remove any of the custom syntax from webweb (double square brackets for links, {{USEAUTH}}, {{NOMARGIN}}, {{HIDENAVBAR}}, etc). Leave the layout set to the default value. Copy and paste the values from page_css and page_js into their corresponding subtabs. If there is anything in page_head, you'll need to make a new layout for the page. Open the new item dialog again, but this time set the item type to "Layout". The title doesn't matter, but I'd recommend something like "[insert page title]Layout". Then, you can add the page_head value into the head element in the new template. Finally, set the layout in the new page to the layout that you just created.
The templates table has the same fields as the Pages table, except page_name is now name, is_staging does not exist, and there is a description field. You can use the same instructions for migrating pages to migrate templates, except choose to make a new template instead of a page. In addition, there isn't a way to add a description to a template in webweb2. If you still need to label your templates, add a comment at the beginning of the Razor subtab of the template.