how to fix a ford 4000rds radio code?

i have posted another question about this but did not understand fully what i was doing anyway im a donky i changed the battery on the works van now i have my stepdad talking to me all day about like and other things STOP THE STEPDAD please can some 1 help me with a 4000 rds serial M029867 i would love to here from any 1 plz plzzzzz