Just install this module as a normal Xoops module.
If that is done, go to your blocks adminpage to display your mainmenu in TreemenuXL style. Don't forget to look at the permissions!
This is a module to link from any source within your xoops installation to any target within your xoops installation. The links will be displayed in an extra block.
This modules is heavily based on tomsys "relations" module. I hope he won't mind that I took his code, changed it and published it under a different name. Original copyright notices are still intact.
The module comes ...