Didn't say it was easy, just a DIY science project.
Tried USB adapter posted above to SATA Drive DOCK worked once for me then crashed, maybe because Dock has own power source separate from *C receiver. I might try it again if can get it powered up/down in sync from Receiver itself.
Had a failed DSR530, took Hard Drive connection out of it, used soldering iron to remove power plug from it and install on opposite side, this allows plugging some connection wiring and adapters in on one side and power on other. Glad I didn't toss dud receiver out.
Removed the metal cage in rear left side of Receiver and unplugged from Motherboard. (I understand this cage and its connection to motherboard is for some future upgrade that has never arrived, receiver runs fine without it plugged in as nothing is connected to it) This gives room for extra wiring and adapters on end of hard drive to be put together. Sticks up about 1/2 inch too high to get top of receiver on, seems to work fine, have used for a week and DVR is definitely faster and smoother. Will cut a hole in my spare receivers top cover for adapter board to stick through or look at getting heat sinks to move down farther on their mounts so everything drops down a bit or a stop of some kind to hold back of cover up a bit on back side.
I would only do this if you can get spare *C drive connection board, or if your a better solder than me, you could probably put another plug on rear of board so power plugs were on both sides? (check with resellers for broken DSR530 for parts, E-recycle places, or ebay)
Used these items to build a adapter setup, [*C board to SATA]
Plug into everything, to have:
*C board+Startech Adapter+SATA Drive
Run the Tiger power cord, from *C board plug that was moved then around and use small 4 prong connection to plug into Startech adapter to power drive.
Jumpered SATA drive down to SATA1, as don't need SATA3 speed with USB
Watch that Startech adapter is installed so missing pin is in same spot as it is on OEM drive when plugged into *C drive mount board
Used small side cutters (4" tall) to remove security screws, tips of cutters go into screws groves and twist out quite nicely.
Got a couple of these fans they plug into USB ports on back of receiver, one blowing in removed doors at back of receiver and another blowing on side, things are nice and cool.
Need to check the power usage comparing OEM drive and the SATA, as I forgot to check that out ahead of time.
This is drive I used
Might try a 2 Terrabyte drive next !!!!