Let's start by opening the Computer Maganement plug-in of the Microsoft Management Console with
If asked, enter the Administrator password, or confirm you want to run it as administrator.
Right-click on the SSD Card, and pick Change Drive Letter and Paths, then choose Add, select a letter different than any of your existing drive letters and then click OK.
I'd avoid A: or B: since you may use that camera with another app someday, and I have read some older apps can act strangely if they see a drive A; or B: larger than a standard floppy disc.
Close the Disk Management console, and your device should appear with that drive letter henceforth.