Around 6 months ago I made some research and migrated to Disqus commenting system by simply installing the plugin. Of course I exported all my comments from default wordpress to Disqus. My intetsion of using this system was to well manage my all comments and provide better visibility to the users, like a user could register with any of his or his social login or even with discuss login. One reason was Disqus also provides, efficient comments customized options.
I exaplined some good features of Disqus but the bad impact i faced is, my all comments (previous & new) were deindexed by google as Disqus system runs with Java and Google or other such crawlers can not read Java code from the page's source code. If you check your disqus enabled page source you will not get much information about your comments. So now my problem was how to import all my Disqus comments back into wordpress default system.
I made a lot resourch on this to find a way where to get my comments back, I even found import option in the Disqus's admin panel, I exported the Disqus comments to my local system in XML format, now i was searching on the web so I import these comments into wordpress but in most of the online tutorials I saw shows, this is not possible, by surffing on the web I got feeling like wordpress import option doesn't understand the disqus generated XML format file, also I went through some other different thoughts but I couldn't find any ultimate method which help me to import these comments to wordpress.
Now what i have done to get my old and new all comments back without any issue. Woww It was very simple, what I did is, I Deactivated the Disqus plugin and Oila!! I still see the Disqus comments in the form of wordpress's default commenting system. No rocket sicence, it was very simple and easy. If you want to do the same, please make sure you have updated wordpress. Also donot forget backup your WordPress database before executing any such activity on your blog.