Hello guys,
Here are i0nNepgear and his shinki Ariel. Recently Ive got a nice cradle for her, which she likes a lot and also cost me a leg. But, it's kind of useless, becuz it literally just lit up when you plug it into ur computer. It occupies a USB port but does nothing useful (for me at least), like someone occupies the washroom without taking a dump. So, I decided to make it more useful--by putting an SSD into it. I'll talk about the steps later, but first here's a photo the finished product and Ariel lying on it:
(P.S. I'm still learning English, so sorry if I make any mistake ;P)

I'll write the tutorial now. If you also wanna mod your cradle, make sure you know what you are doing and operate carefully.
I'm not responsible for any damaged cradle or SSD. You have been warned (-`д´-)!

What you'll need:
A Shinki Cradle (obviously)
A 2.5 inch SSD (Samsung 850 EVO 250GB/120GB recommended bcuz their BCP are small enough)
A USB to SATA cable, better with status indicator light. heres what I bought: https://www.amazon.ca/gp/product/B011M8YACM/
(You can also use some other kinds of cables or SSDs, like a M.2 SSD or mSATA SSD.)
A nice screwdriver

If you want to modify the LED into a hard drive status indicator (or at least a power indicator):
Soldering iron
Some jumper wires
A 5mm light emitting diode, aka LED (Use the one in the cradle if you want. You can also use RGB LED like me.)
A resistor, 100-200 ohm (USB ports provide 5V DC current while LEDs usually work at 2-3V. Connecting the LED to the USB power without any protection will kill the LED. However, you don't need the resistor if you want to directly replace the status indicator on your USB to SATA cable becuz it's already 3V.)
A few 1mm heat shrink tube to prevent short circuit.

Optional stuff:
Hot glue gun and glue sticks (Use this to strength the wires connected to the PCB of the SATA module. They may easily break after you remove the plastic cover, and that'll be extremely hard to resolder them in place. So apply the glue before this happen)
Some sponges or other kinds of filler that can stop the hard drive from moving in the cradle
A small heatsink to dissipate the heat generated by the SSD controller (It's like a small CPU that controls the SSD). This is what I bought: https://www.amazon.ca/gp/product/B010ER7UN8

In this photo, you can see how I connect my wires. Note that resistor wrapped in the heat shrink tube. That wire connects the green pin of my LED to the USB power. Another red wire without the resistor connects the blue pin to the anode of the removed mini onboard LED, used as the status indicator. And the black wire connects the common cathode pin of the LED to the USB ground.

After you get all your things ready, it's time to start working!
First, disassemble the cradle and remove the wire and the small PCB. Cut the LED off the board if you need it.

Ariel: Oh, so that's everything in my cradle!? ((((；゜Д゜)))
Me: It's just a light, what were u expecting?? ╮(￣⊿￣")╭ I'm thrilled it actually has a small piece of PCB in it. And DON'T TOUCH MY HOT GLUE GUN, it's HOT!! Σ(゜ロ゜;)

Next, you need to (crack) open your SSD and take the PCB out of the case. Remember doing this will void the warranty.

With the help (force, actually) of her, the SSD was opened (safely).
NOTE: BEFORE you touch the PCB, you MUST ground yourself. You don't want to kill your SSD (which costs u 200 bucks) with electrostatic discharge (aka ESD).

Forgot the picture.

And here is the PCB inside the SSD case. While I think it's so small, Ariel doesn't think so.
Ariel: Master, how much stuff can u put in this huge (?) thing?【・ヘ・?】
Me: *Look at the manual* 250 gigs, actually formatted capacity less. ﾍ(￣ ￣;ﾍ)
Ariel: That's rubbish... The storage inside me is nearly 4TB! （￣へ￣）
Me: Well you're from 2040, what do you expect from technologies that are more than 20 years old?? (ಠ_ಠ)

Plug the PCB into the cables SATA port, and now it's time to put the whole thing in the cradle. First, slide the LED back in place.