1.  RENAME THE FILE EXTENSIONS:  change .nsf to .sav (bandcamp only allows uploads of certain file types, although I wholeheartedly approve the fact that they allow NSF files)

2.  Make a copy of your LSDJ rom that has the same filename as the save file you want to open (so if you changed the file to Roots1.sav, your LSDJ rom should be called Roots1.gb) and put them in the same folder. 

3.  Make sure the two files (rom and save file) are in the same folder.  Open the rom in BGB, or upload to your gameboy cart.  If you're using a mac it can be done but it's complicated and I can't help you.  Google is your friend.

<3<3<3 danimal cannon