Per Dell-Cares team, the system only has one SSD slot.  The system specs can be found here. Instructions for removing and installing the drive can be found here.
Hi, I would like to learn how to upgrade the SSD on Dell Latitude 7520. I have never upgraded storage before hence a step by step guide is highly appreciated.  Do we have extra slot for the SSD upgrade?  Also does the SSD come with brackets and screws to hold it?  Looking forward to your help. 
How can I upgrade storage on Dell Latitude 7520?