Upgrading from Modus Bootstrap 1

Steps

There is a command-line script designed to help you upgrade your Modus Bootstrap 1 (based on Bootstrap 4) projects to Modus Bootstrap 2 (based on Bootstrap 5). It uses gulp with gulp-replace to replace class names within your folder of HTML pages/templates and it can save a lot of time.
Check your JavaScript/TypeScript files don’t use deprecated/renamed classes and update as necessary as the command-line script in the step above is only really for HTML-like templates.
Update any of the CSS imports on your project to remove any @trimbleinc/modus-bootstrap imports and instead just use a single import which includes light mode, dark mode, modus-layout and everything else you need.:

@import '../node_modules/@trimble-oss/modus-bootstrap/dist/css/modus-bootstrap.min.css';`

Modus Bootstrap doesn’t include Print styles, though you can use bootstrap-print-css from npm.
If you used negative margins/padding classes (e.g, .mt-n1 or .pb-n2) note that these are not included in the CDN version of the Modus Bootstrap CSS so you may want to add those.
Remember that there is a new XXL breakpoint so be sure to make use of it and optimize layouts for screens larger than 1440px.
There is a helpful browser extension which can be used for finding any deprecated classes on your site.