If you can tell me (e.g., Dreambox, Openbox), I can give you more specific, step-by-step instructions on how to load the keys.
Receivers running Enigma2 (such as Vu+, Dreambox, Zgemma, and Formuler) are the most flexible. They do not rely on factory-patched firmware. Instead, they use standalone softcam plugins: latest softcam keys for all receivers