I've done this Hack on my DS2072A-S, so if it works with this one, it will also work with any other 2xxx.
Here is, what you have to do:
1) Download
https://mega.co.nz/#!MdcEWTgL!0EEmSr-Q6TxaFSsyEmjhRrgqDvFCoXg9K49BalL5Uxc2) Install this firmware during bootup - check Rigol's guide on how to do that
3) Connect the scope to a PC using USB.
4) Install and start "Rigol Ultra Sigma", right click on your scope, open "SCPI Control Panel" and "Send&Read" string "*IDN?"
5) Copy string from comma after serial # of your DS2xxxA to the end ("02008400...").
6) Open HEX editor, create a new file and paste string as HEX (not ASCII).
7) Copy serial # of your DS2xxxA.
Append serial # as ASCII to the data in HEX editor.
9) Append "00" as HEX.
10) Save file as "keyfile.bin" to folder with "rigup" (
https://mega.co.nz/#!qAkUkTZB!XG12bUKhIz4CmQt6DbBnGRMvEe5AvUjEaBxi4R03tw8).
11) Open command line and navigate to folder with "rigup".
12) Execute "rigup scan keyfile.bin" and get some keys:
RC5KEY1: 88359067012Exxxxxxxxxxxxxxxxxxx
RC5KEY2: 3D44CD4EC48Fxxxxxxxxxxxxxxxxxxx
XXTEAKEY: 95F6CC12864Axxxxxxxxxxxxxxxxxxx
PUBKEY: 006CE7F7xxxxxxxx
PRIVKEY: 008ABBC4xxxxxxxx
SERIAL: DS2D154xxxxxx
13) Copy them to another text file "keyfile.txt" in "rigup" folder.
14) Execute "rigup license keyfile.txt NSxx", where:
NSEH (0x1C087) - All options
NSER (0x1C08F) - 100 MHz + all options
NSEQ (0x1C097) - 200 MHz + all options
NS8H (0x1C0C7) - 300 MHz + all options
15) Copy license key.
16) In "Rigol Ultra Sigma" -> "SCPI Control Panel"" -> "Send&Read" ":SYSTem:OPTion:INSTall YOURLICENSEKEYWITHOUTDASHES".
This is Variant b.
Thx Fagear for the instructions and of course big thanks to zombie28 and tirulerbach, who made this hack possible!