This module is based on the 2checkout payment module.
To install this module, download and extract the archive to your site's Ubercart's contrib directory and enable via Site building -> Modules. You can set your own settings in the Store administration -> Configuration -> Payment settings -> Payment methods.
You need to set your Merchant Account's Post Back URL to: http://www.example.com/cart/payeasy/complete or https://www.example.com/cart/payeasy/complete if you're using ssl. Note that if you're using securepages module, you need to add login2.asp and Pay.aspx to the pages that will be secured or a 404 will result upon submitting all the info to the PayEasy site.
If there are any issues, feel free to submit an issue.