Buy a USB Hdd, not a massive one, some boxes
don't see really big ones (about 500Gb, or less will do fine).
Format to FAT32 (some come pre formatted)
Plug it into the box.
You have a record button at the bottom of the remote
for instant recording.
For timer recording press the micro panel button (m/p)
Timer Settings - Ok
Change timer settings to "once or daily " (right button)
Timer service to "record" (right button)
Set channel,date,time and duration (like setting an old video recorder)
Save.
If your box is going to be on standby, start recording a bit early as it only starts booting
from the time you have set.