There are several ways to install psd-manager 4 on all your machines. The easiest is to simply install cebas product manager everywhere and install it this way. You just need to login using your cebas.com account once on each machine.
If you want to install/update in a central location - look at the psd-manager 4.0 description within the product manager - there is a section about network deployment. However, this is not the only way to do it if you know your way around 3ds max and installing plugins. psd-manager 4.0 currently requires no files to be installed directly in the 3ds max root directory so you also can use other means to copy/share the psd-manager plugin files.
psd-manager plugin files are installed by the product manager at this location: