The solution is a bit tricky and its called
mklink. Mklink is a windows command that can link 2 different directories in 2 different locations and so when an application is trying to access "c:\Program Files\Microsoft Office\" it will actually access "d:\Program Files\Microsoft Office\" or any drive. The process is transparent and office won't even know in which disk is installed, but it will think its still C:
Note, I don't have office 365 at the moment and so I can't fully test this, so you might need to do a bit of experimenting, tweaking, and research on the solution for your PC. I do use mklink tho for some other solutions and know it works fine.
Officially, Microsoft is saying this:
"You cannot customize the installation location for Click-to-Run for Office 365 products. Click-to-Run can only be deployed to the system drive which is typically drive C. "
We are not MS tho
Step1: You either need to be in safe mode or use an App called lockhunter. Office folder is locked by the system so when you will try to move it you will get some errors. In safe mode or using lockhunter you can "unlock" the office folder for what we will do next. You will also need to locate, which folders the office is using. On some PCs its any of those or a combo of 2.
C:\Program Files\Microsoft Office 15
C:\Program Files (x86)\Microsoft Office
C:\Program Files\Microsoft Office\
Step2: Create a folder in the destination drive -
D:\Program Files\Microsoft Office where
D is your drive letter. Don't forget to do the same if you have a
C:\Program Files (x86) entry and make sure spelling is exactly the same.
Step3: Navigate to
C:\Program Files\Microsoft Office and move (cut & paste) the content to the same folder on the other drive. If you are in safe mode or used lockhunter you wont get any prompts (file is in use) or asked for admin rights. Do the same for other folders if they exist
Step4: Delete
c:\program files\microsoft office folder. Might ask admin rights again. Do the same for other folders if they exist. The reason you need to delete the folder is that Mklink at step5 cant operate on an existing folder and needs to recreate it.
Step5: The crucial one. Open the command prompt and type this:
mklink /J "C:\Program Files\Microsoft Office" "D:\Program Fiiles\Microsoft Office. That will create the folder again on C and link it to the other drive. By using MkLink, every time windows is trying to access c:\folder it will go to the redirected d:\folder.
Enjoy your office on the other disk.
If things go south, you can always just remove and reinstall office. I would advise you before you begin, to google the above command(s) to be sure of what they do and what you are doing.
I hope it helped and let us know how it went.