The RIGOL MSO series have a different encryption than the DSOs. Thus you need a JTAG cable to dump the memory and extract the keys.
Basically you can just follow the steps in https://www.youtube.com/watch?v=OvcGn_ScG5w
However, at the step when you need to generate the keys with
./rigup license [keyfile] 0x1C0FF, do not just run the command. Run
cat [keyfile], and compare with the device serial you obtained by SCPI IDN command. You will discover that the serial number is wrong.
rigup scan - Version 0.4.1 Hacked up for MSO1000Z(-S) rmd79, 0ff eevblog.com RC5KEY1: 9BBBBBBBBBBBBBBBBBBBBBBBBBFAD3E6 RC5KEY2: 8BBBBBBBBBBBBBBBBBBBBBBBBB0A699C XXTEAKEY: 8BBBBBBBBBBBBBBBBBBBBBBBBB24850B PUBKEY: 00XXXXXXXXXXXXXX PRIVKEY: 00XXXXXXXXXXXXXX SERIAL: DS1ZA203000000 [ This is WRONG ]
Replace the serial number with the one you got using SCPI
Now you can generate the license with
./rigup [keyfile] mso1100z.txt 0x1C0FF.
And install with SCPI
Voilà! Now you have a scope with all options unlocked.