I tried to install (for the first time) and I tried to do the installation like I always do, through the extension manager.

The page appeared to be timing out (due to my internet connection it sometimes happens) so i pressed the upload and install button again with no success, nothing seemed to be happening. I then tried to go into the backend index.php but it appeared to be blank. I don't know what to do. Should I manually remove every folder created by k2? is there an easier method?

I am using Joomla 2.5.7 and tried to install K2 2.6

On a furher note (possibly a case of incomplete upload) heres the error in the admin folder

PHP Fatal error: Class 'K2Model' not found in /myserver/plugins/system/k2/k2.php on line 360

I managed to manually delete the specific error folder and the administrative page returned.

But another failed attempt while trying to install k2 2.5.7

PHP Fatal error: Call to a member function getLatestItems() on a non-object in /myserver/administrator/modules/mod_k2_stats/helper.php on line 18

I got this after upgrading:
Fatal error: Class 'K2Model' not found in /mysite/components/com_k2/models/itemlist.php on line 18

Where do I go from here?