In the ACP go to XenPorta > Blocks and Install the block using the XML file included in the package. Once installed, click on the block to configure it. Then in XenPorta > Layouts drag it onto the layouts you are using.
Configuring the time period for this add-on is done via its own settings in the ACP Options. However, and I'd be grateful if you could check this and let me know, I think there's a bug in the XenPorta block as no matter how I configure the time period, it always says at the bottom of the XenPorta block "last 0 hours" instead of the time period specified. It works fine on the standard sidebar block though. I have reported this to @
Chris Deeming but it would be useful if you could see if the same happens to you or not so we know if it's a bug or a problem on my forum. Thanks.