In the upgrading process, Vue has provided us with two ways to update our project. The first way is to use the Vue-CLI plugin, which tries to automate almost all the processes and changes needed for the upgrade.
The second way is to upgrade the project manually. This method requires the developer to upgrade all the dependencies to the latest version, install the new single-file component compiler, @vue/compiler-sfc, and change the entry files for the Vue application, router, and store to the new API.
Following the changes to the starter structure of the project, the developer needs to check the components to see whether there are any Vue 3 breaking changes present, refactor the component to the new Vue 3 APIs, and remove the deprecated APIs from Vue 2.