Register domain that you want in Namecheap. You are free to use .com .net .org .info or whatever you want. This time I use domain .info
Log in to your Blogger account, then click Settings > Basic > +Setup a 3rd party URL for your blog
Type the domain address that is previously registered in Namecheap, and then click Save. Make sure you use "www" part
It would appear an error "We have not been able to verify your authority to this domain. Error 12. " Do not worry. Notice that there are two CNAME records below. Go on to step 6
Open a new tab in your browser and log in to Namecheap account > My Account > Manage Domains > yourdomain > then on the left menu bar, click "All Host Records"
Enter data CNAMEs as it is presented below and then click Save For @ field you put http://www.yourdomainname.tld/ (make sure you put your domain name and do not forget about the http://www.)
Back to blogger settings page and then click Save
Now you have TLD (Top Level Domain) in your blog. Old domain (*.blogspot.com) will be redirected automatically to the new domain.
During the making of this tutorial, custom domain www.simpleblogger.info can be directly accessed shortly after I click the save button. The redirecting process from the regular blogspot address to www.simpleblogger.info also works instantly. This is due to this blog is a new blog that I have just made. But if your blog is quite old, this new changes of domain will just have an effect after 3 hours or more. If there are steps that are not clear enough, you can ask in the comments field.