... edit your includes/paging.php according to your requirements ...
... in default paging.php find starting from line 80 to change ...
$this->desc = $lang['paging_stats'];
$this->paging_next = $lang['paging_next'];
$this->paging_back = $lang['paging_previous'];
$this->paging_lastpage = $lang['paging_lastpage'];
$this->paging_firstpage = $lang['paging_firstpage'];