Here is a short guide on how to make multiple mn's work on the same VPS:

1. Create a new folder
2. Copy folder blocks (thats inside .helix) into that folder
3. Copy helixd and helix.conf into that new folder as well
4. Change rpcport(dont use 37415-37418) and masternode priv key
5. With the terminal go to that new folder and type "touch mnstart.sh"
6. Open mnstart.sh and type "./helixd -datadir=./"
7. Save mnstart.sh
8. go to the terminal again and type "./mnstart.sh"