open both files in NOTEPAD (they are simple text files) and copy everything BELOW the local host line from one file to the other (pasting it in at the end of the file).
The localhost lines to look for are near the top of the file and will show as either:
depending on how the file is set up (large ones often use the 0.0.0.0 as it can be quicker).
Once you open the files you should have no problem figuring it out.
I want to add the MVPS hosts files to the existing hosts file I have (primarily from Spybot) - how do you add this file to the existing hosts?