Reinstalling Ogone payment option

-- HikaShop version -- : 2.3.3
-- Joomla version -- : 1.5.26
-- PHP version -- : 5.3
-- Browser(s) name and version -- : Firefox

I installed Hikashop a short while ago and because i wanted to save space on the hosting server, i deleted the many payment options i was not planning to use and only left credit card and paypal. However, now it turns out the client wants to use Ogone as well. I still have all the files for the Ogone plugin, so I zipped them and tried to install the plugin, but i got a 'no install file found' error. Then tried to add the files in the right places manually ("public_html/administrator/components/com_hikashop/extensions/plg_hikashoppayment_ogone" and "public_html/plugins/hikashoppayment" ) but ogone still doesn't show up as one of the payment options in the hikashop backend interface so i guess i missed something here. So my questions is: What is the easiest way to install the ogone payment plugin again after deleting it when i have the necessary files at my disposal, but just gotta install them. Thank you for your help.

Okay. Is there a lot of extra work if i would not reinstall the entire hikashop but still try to install the plugin on itself? (I already configured things, will that data be lost if i reinstall?)

Thank you.

I I uninstalled and reinstalled Hikashop but now i have a an even bigger problem: Hikashop said the installing went perfect but now i don't have a single payment option showing under "system -> payment options". When i check the list of installed plugins in Joomla itself, all the hikashop payment options are there and active but the list under "hikashop -> system -> payment options" stays empty. How can this be?

Edit: Hmm, seems it was a weird hickup somewhere. After reinstalling again, they do show up again. Weird.

Thank you.