I'm not sure I can answer you request fully but here is what I just had to do.
I needed to change the line feed ( 0x0A ) to a space (0x20 ) in a file that takes the form:
so I could copy and paste them after 'rm -f' into one long line.
My copy of "Linux in a Nutshell" shows as an example:
tr ' ' '\012' < file
Which is the exact opposite of what I wanted. Simple swap gave me the desired results.
Be aware that 'tr' requires the numerical input to be of type octal.
So if you've got 3 values to change you might write a script that call 'tr' 3 times. Once for each value.