The SAPGUI is available to you on the Software-drive at the computer center. On the CIP-Pool Computer you can find it here:

F:\S\SAP\SAPGUI\SAPGUI 7.40 Compilation 3\

or

\\fs.hs-regensburg.de\storage\software\Pool\S\SAP\SAPGUI\SAPGUI 7.40 Compilation 3

To download it outside of the university network, and to connect to SAP from outside, you need a VPN-Connection.

The instruction to establish a VPN-Connection can be found at the Support-Wiki of the computer center. The instruction to connect to "drives" can be found at the Support-Wiki again. Also see "External Access to the SAP-System".