This tutorial is only on PCs.

You will be needing a software for checking/creating file hash. If you don't have one, you can use QuickSFV.

http://www.quicksfv.org/index.html

Let's start changing MD5s. Say we have the files below that need MD5 change:

Code: 
FILENAME        SIZE        MD5 hash
bolt.part1.rar         1,500,000     499934d3cc1c544c37f6f5d985a13685
bolt.part2.rar         1,500,000     a572b15572a7715df83e093ee2fb2bf9
bolt.part3.rar         1,500,000    c1291527060c81b590356195cdd18367
bolt.part4.rar           416,344     a7d6ddfedc3d273ab91d46c389d110d8


Open notepad and type one RANDOM character, say "a" in this example, then save the file as MD5.txt

Open another instance of notepad and type the line below:

Code: 
FOR %%1 in (*.rar) do COPY %%1+MD5.txt


Save the file as ChangeMD5.BAT


RUN the batch file, ChangeMD5.BAT, by double clicking on it.

Filesize and filehash would be changed to:
Code: 
FILENAME        SIZE        MD5 hash
bolt.part1.rar         1,500,002     815890400fa58d4010bf858fbe2d2c88
bolt.part2.rar         1,500,002     6b1dce05c261fe217d365077e9dd632c
bolt.part3.rar         1,500,002    250750017453d1fd70e77466b94d5dec
bolt.part4.rar           416,346     d6d90760657d4cc37d9b34fc44e19dc5
NOTE that the file sizes are now 2 bytes more than the original. MD5 hash changed as well.

Open WInRAR and test the archive. There must be NO ERRORS in the test operation. If tested OK, you can now upload the file to your preferred filehost.

I have been using this method for a long time to modify the MD5s of files that i upload. You can test whether this method can also be used on ZIP files. I would not recommend using this method on movie files because this will modify the original file. You don't want that. You should RAR the files so that you will just be modifying the CONTAINER and NOT THE CONTENT.

Source:
Bolt