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've been able to do A/B comparisons with an Aurender N100h (similar in price to the HAPZ1 + mod) and a Melco. The Melco came close, but lacked the last measure of bass articulation and heft. The Aurender has superb timbral accuracy, but blurs a bit in complex passages or highly arpeggiated music, such as Wuorinen Bearbreiten.

You're probably aware of Presto Music, but they have an excellent selection of Hi-def flac downloads at reasonable prices.

Get the Mod and be as happy as you deserve! 

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.  

I decided to get the Modwright upgrade to my HAP Z1ES, and I had them install the SSD. So, I can't help you. Sorry. I can speak in general terms.
The HDD native to the HAP will look nearly identical to the one you bought.  
HDDs are usually mounted in fitted racks with (I think) four screws on each rail (that is, each side). The screws go through the rail into threaded holes in the HDD case. The drive will have a ganged connector for power and another for the data bus. Unplug these first. Do this only with the HAP powered off AND unplugged. Remove the screws in the rail and the HDD will slide out easily. Note how it was oriented in the anchor rack and orient the SSD the same. Plug in the connectors, being sure they're properly seated, and slide the SSD in the rack until the mounting holes align. You want the screws tight, as vibration will degrade the performance of the drive. 
Again, that's how it works inside a computer; I'm assuming the HAP is the same, but I've never seen the innards of the HAP myself. 
If you live near an audiophile retailer, you may be able to get advice from someone there. Remember, these things are assembled by people working cheap. If they can do it, you can too. 
Sorry I can't be more helpful. 

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!).