The zip does not contain a module manifest, so you can't install as a normal module.
Just follow these easy steps:
Prerequisites: install XsltDb first, this module cannot run without it!
1) Download and unzip locally
2) Copy Trapias.cs to your App_Code\XsltDb folder.
3) Copy all files in the js folder to your DNN site under
/Portals/_default/js. Adjust paths in the xslt if you want to place js
files in a different location.
4) Create a folder named XSLider under your portal root (for example:
/Portals/0/XSLider).
5) Create a new XsltDb module instance in a page of your choice, open
the .xsl file with a text editor (e.g. notepad) and copy its content
into the XsltDb editor. Save and publish.
6) Open your new module settings and configure as needed.