I don't think the hack is finished yet.
When it is it will just be "a) Download this file onto a USB stick, b) Insert stick into 'scope".
I don't think the hack is completely finished, there are still so many bugs even in the latest firmware that a new firmware release is bound to come out and may need to be re-hacked.
However, I did receive my 5074 today and it was as easy as downloading the file and inserting into the scope. It took about 45 minutes of reading through posts though. I purchased this scope over a month ago and it has been on back order. When I purchased the scope and checked the forum, the hack was as simple as SSH and editing a line in the start file. After reading through tons of off topic posts and stories I found the solution, at least as of now.
All I did to unlock the scope was
a)download and copy the file onto my fat32 formatted usb drive.
I got the file from this post
https://www.eevblog.com/forum/testgear/hacking-the-rigol-mso5000-series-oscilloscopes/msg2235282/#msg2235282(I also had to rename the file to DS5000Update.GEL)
b) plug the flash drive into the scope and run a local upgrade
c) enjoy the unlocked scope
I did not bother backing up the calibration data as my scope came with firmware version 01.01.04.04 and had a messed up calibration out of the box consistent with how others have described the calibration with the new firmware.