text before readmore not visible in article

-- url of the page with the problem -- : www.air-learning.nl
-- HikaShop version -- : 2.2.2.
-- Joomla version -- : 3.2.1
-- PHP version -- : 5.5.31-0ubuntu0.12.04.1
-- Browser(s) name and version -- : all
-- Error-message(debug-mod must be tuned on) -- : none

For my website im looking for a way to remove the text before the readmore line when display the full article.
the readmore line must only be visible in the article list but not when opening the full article..

i know that this is posible but my question is how.