As long as the other copy of SW is not running, the licence manager should automatically elevate your copy when you start a "premium" add-in.
This presupposes your using the SNL though
You will need to first transfer the licence from your colleague's machine using the Help>Deactivate licence.
After this you will need to modify your SolidWorks serial number. Control Panel> Add/remove programs> Solidworks 20xx> Bight mouse button> Change> then follwoing through the installation manager you will need to change the serial number to your colleagues licence number and then make sure all products have been installed that are a part of SW premium.
Then once you reopen your SW you will reactivate the licence as a premium version.
Yes, you can but its kind of messing up the serial number
it's be much easier if you can use his computer while he's gone for the meeting or not there for some reasons?