I have a Dell 15R 5537. The drive removal is about the same. There are only two screws holding the drive, though. They’re located at the back of the drive. Push the drive back to clear the connector and pull up aided by a clear plastic pull tab on the drive.
Shoot! My Dell Inspiron 15R is different. Mine has an almost full length cover (11.6”) by 3” wide on the bottom. The hard drive and memory sticks are under that cover. I’m just not sure what else to remove to replace the drive with an SSD.