I don't know whether this is discussed or not, but if someone tries to find a wat to do this, i first imported all of my jcomments comments into k2-jcomments comments. Then i tried to import them into k2-comments and i can do it so. But jcomments is much more complicated then k2 comments. The only thing that made me import all my jcomments to k2 comments is gavick's postnote template has an error for using jcomments plugin that they didn't give any help to fix it. So i imported everything to k2 comments. That is how i did this. (beware to make a backup of everything and know that it needs a medicre mysql usage knowledge) - First i checked my joomla article id's and k2 article id's. I saw that they are the same, that gave me the idea. Also i saw that it uses "com_content" and k2 comments uses "com_k2"- I installed jcomments k2 plugin.- Then entered into phpmyadmin and find jcomments table from mysql. - I exported the table. Then i opened jcomments.sql (or whatevername i give) with wordpad. - I changed "com_comment" to "com_k2" with find and replace function of wordpad.- then i dropped jcomments table from database and imported sql that i changed.- Ta daaa jcomments are all there. :) ( I hope i didn't forget anything)In the second step i imported jcomments to k2 comments. This is much complex.- i exported k2_comments table then opened it in wordpad. Then i copied everything under jcomments under the line "table structure `jos_jcomments". Then copied it under the line "table structure jos_k2_comments`line under k2 comments sql.- i changed "jos_jcomments" to `jos_k2_comments` with change replace function of worpad in k2_comments.sql that i changed.- Then i dropped k2_comments table, and imported the file that i created.- Then i opened the table structure of the new table i created, but now i know that i had to fix it into like k2 comments table structure.- I don't have a table structure before, may be before dropping table, you can take photoshot of every step of k2 comments table structure. I have another joomla site that have k2, so i opened its database and make everychange by looking to this.- i deleted fields that i do not need, and changed the names of jcomments structure as like k2's comments.- Then when i checked my site, every comment is there. :) Now i can use k2 comments with existing jcomments in my site without losing anything.I hope this helps and gives the idea of people like my situation. I'm not an expert or pro. But that is a way that i can succeed and i want to share it with you.Thanks.