Basic skeleton preparation:

1. Remove unnecessary modules in the folder src/app/modules. (!!!Except auth, i18n and errors folders).
2. Comment unnecessary routes in the src/app/pages/routing.ts file. [9-45] rows.
3. Clear Dashboard src/app/pages/dashboard.component.html file.
4. Clear Dashboard module src/app/pages/dashboard.module.ts file (!remove WidgetsModule from the code, rows [5, 17].
5. Remove Widgets src/_metronic/partials/content/widgets folder and the file src/app/_metronic/partials/index.ts file comment row [3].
6. Clear Aside menu in the file src/app/_metronic/layout/components/aside/aside-menu/aside-menu.component.html. Keep only Dashboard menu item. (For demo1 also need to clear src/app/_metronic/layout/components/sidebar/sidebar-menu/sidebar-menu.component.html file)
7. Clear Header menu in the file src/app/_metronic/layout/components/header/header-menu/header-menu.component.html. Keep only dashboard menu item.
8. In case if you don't need Authorization module, you can remove it also: Remove folder src/app/modules/auth.
9. In the file src/app/app.module.ts comment [12, 18-25, 47-54] rows.
10. In the file src/app/app-routing.module.ts comment [3, 6-10, 18] rows.
11. In the file src/app/_metronic/partials/layout/extras/dropdown-inner/user-inner/user-inner.component.ts comment [4, 16, 21, 26, 30-33, ] rows. In the file src/app/_metronic/partials/layout/extras/dropdown-inner/user-inner/user-inner.component.html comment [1, 161, 2-20, 158-160, ] rows.