Right now I have a Tech Blog Techbymak on the Blogger Platform and there are total 64 pages are Indexed in Google But Now I have Decided to purchase a domain and Transfer it to WordPress so I want to de-index all the page at this time and I want to start my journey from the start.
Instead of removing them all from Google and hurting your ranking, you should try setting up 301 redirects.
> If you need to change the URL of a page as it is shown in search engine results, we recommended that you use a server-side 301 redirect. This is the best way to ensure that users and search engines are directed to the correct page. The 301 status code means that a page has permanently moved to a new location.