Hi, if you down loaded Kodi from there site then you would normally then install from a zip file there wizard.
You can get in touch with droidsticks via there twitter account or give them a call. This forum is mainly for droidbox and that's a different company to droidsticks.
You could try and manually install add-on by adding there repos, if you no how to install them try installing the Metalkettle repo as this has a droidsticks help centre on it witch may help you.
http://Kodi.metalkettle.co
Add this in the file manager in Kodi, then add source, in the top box put the link in and bottom a name. Then click done, go back to system click here then add-ons, then install from zip. Click on the name you gave it and then install the repository.metalkettle-1.5.1.zip
Then go back to add-on after its installed and click on it then go to Metalkettle and install what you like.
For more repos look on YouTube.
If your box is from droidbox send them an email using this link and they might send you the zip for the droidbox wizard.
http://www.droidboxforums.com/threads/what-to-include-if-you-need-to-e-mail-us.364/
Dave