The safest and fastest way to do this would be to make a disk image, copying everything on the SSD, including system and hidden files, using a third-party tool such as Macrium Reflect Free. Because this uses direct disk I/O, rather than moving a single fle at a time and then creating anew the file system information, speed depends on the total size of the image, not number of files. On my PC's, using slow HHD's (not fast SSD's), speed is ~100 MB/second.
After the image is created, you can moun the image as if it were a disk drive and browse individual files. And, as an added advantage, should your SSD fail, you can restore the whole operating system, as well as data, from the image, to a new drive.