Replace HDD in Sony HAP Z1ES with an SSD

I, too, play violin (badly) and am wondering about the BIG expense of modding the HAP Z1 (just purchasing one now). I want to expand internal storage to 2TB with an SSD, but am wondering if it really sounds $3000 better when getting the 'serious guts' modded?  I listen to classical and orchestral and some jazz.  With eyes closed/blind test, is the difference really 'night and day' between the unmodded and the modded player?

I bought a 2.5" Samsung EVO 960 SATA hard drive (the size of the hard drive in the machine) and am flummoxed how to even REMOVE the old drive and replace it with the new.  So many screws, difficult to figure out how to physically get the old drive out.  ANY HELP SO MUCH APPRECIATED--especially if it has PICTURES showing which screws to remove, etc.  

OTT,  that was so kind of you to try to help out. I've built many computers and installed lots of hardware inside boxes, so I guess I'll just have to power through and figure it out.  First tries aren't always successful.  It's a LOT of screws to even get the cover off, let alone remove the hard drive from where it's pretty tightly installed.  I'll let you know what happens and maybe take some pictures along the way to help others contemplating the job.  Apparently, there was once a detailed how-to on HiFi-Insider, but that's no longer available (unless someone can help with reposting that article with its detailed photos. MUCH OBLIGED if you can!).

(ouch with grammar mistake: that should be "ITS preselected settings..."

Many, many thanks, Streborx2.  Got the job done with your helpful instructions, but I forgot to take photos as I did the 'operation.'  The HAP-Z1 works flawlessly, and I didn't even lose the sample music that came installed on the HDD (making me wonder: there must be some internal memory somewhere that can hold firmware + some music!). Anyway, I'm beginning the LONG project of ripping about 1300 CDs into FLAC files using DB Poweramp version 16.  So far, album art and cataloging have gone great; it's preselected settings make sense for classical music collectors, of which I am one.  So, multiple recordings of the same symphony, or collections spanning several discs, are no problem with default settings.  whew!