Dalento, all you need do once the channel changes is to press and release the "MUTE" button and it will install the code. (If I missed writing that in the instructions I left earlier in the year, MY BAD!)
If anyone is having trouble locating their code for this unit, feel free to email me with the subject heading of "remote codes" and I will be glad to send you whatever code you are searching for...
Sincerely,
mizzllat2@msn.com