Booting Mass effect 3 from external HDD

Hey Guys.
I’m having trouble booting ME3 from my external HDD. I have replaced the EBOOT and PARAM from the 001 archive and after it split the game installing the data on the internal HDD due to one of the files being over 4GB it shows a disk error when booting. Can anyone tell me what I’m doing wrong? BTW I thought that you simply cannot boot games with 4GB+ single files in them. Why can it be done with ME3?
Thank you for your time.

if you want to play it from external use PSARC to extract that large psarc file, then delete the original file. Check out the TB compatibility thread. It has the download and all the info you need to get it running on external

HAHA sorry i forgot to reply to this, thanks but i took a look at that thread and i find it easier to just boot from external HDD.