Transferring Single Player Map To Multiplayer.

[Ginger Leprechaun]

I've spent hours on my single player world in Voltz with the Technic launcher and wanted to transfer it to multiplayer still in the Technic launcher but when I followed instructions and videos on how to do it, the map loads up but anything to do with Voltz is missing i.e missile launchers, blast proof blocks etc. I have tried fiddling around with the instructions again to see if i missed anything out but i couldn't find anything i have done wrong so can you please help me with what I should do and if possible word the instructions in a simple way because I don't understand most things to do with computing.

Thank you very much.