First you need to have a zip program installed such as winzip or winace or some such thing. Then browse to your mohaa folder in windows explorer and double clik on the pak2.pk3 folder, from the menu that comes up, browse down the list to winzip and then clik ok. Once winzip starts it will show the contents of the pak2.pk3 file. Now there should be a button that says 'Add file' or there should be an option to do this in a menu somewhere. Select this option, then browse to wherever you saved the blood patch and select the folders you want to add and clik ok. That should be all. Maybe easier said than done. Could be a wise move to make a backup of the pak2.pk3 file before stuffing around with it. Good luck!