I am writing a program in Java to modify a txt file but I am very new to java. I have opened the file and read in one line. I can't figure out how to modify the part I need to and get rid of the rest of the stuff.

This is an example of what I'm trying to modify. I want to turn this:

000000000: 00000000 00000000 00000000 00000000 ..J..9J...

to get rid of the first ten characters to the : and the space and change the hex stuff into 0x00, 0x00, and so on until the end of the 0's then get rid of the rest. I can't figure out how to do this any help would be great. I will eventually be doing this through thousands of lines. But I want to get one line done first to modify and the rest should be pretty easy.