Which SSD hard drives on ebay are compatible with the Dell Inspiron 15 7559?

I don't know if your laptop uses a 2.5 in SATA solid state drive or if it uses a stick shaped hard drive if it uses a standard 2.5 in SATA drive then any drive on eBay that's 2.5 in will work.   Now as to getting your material over from one hard drive to another. The first thing that you want to do is make sure the solid state drive that you're buying is bigger in storage space than what you have by just a little bit at least.

The next thing that you want to do is get yourself an external hard drive that's larger in storage space then whatever you happen to be copying.

Now open up the control panel. Go up to the top where it says back up and restore. Open it up in the upper left hand corner you'll see where it says make a system image.

Now make your system image on the external hard drive.

When you're done it's going to ask you if you want to create a system repair disc answer yes and insert a clean unscratched disc. 

Now go ahead and replace your old hard drive with the solid state drive. Insert your disc and plug in your external hard drive. On a day you're going to be using f12 to access the boot menu on Hewlett-Packard it's f9.

You're going to boot tothe DVD drive or the CD drive.

In a minute when it loads up you will choose the option repair my computer.  You're then going to choose the option restore a system image.  

Select that and then hit enter. The restoration process will begin it will format and partition your solid state drive.

And completely restore everything that was on the old physical drive. The whole process takes less than an hour.