You need to have the PC connected to the PLC by a programming cable. Then, you need to load RSLinx and configure the connection to the PLC.
Once you can see the PLC in RSLinx (the RSWho window), you can open RSLogix and download the ladder logic. You'll need to select the path from the communications menu.
You said you were new, but do you know which part of this you're having trouble with? It will help us to be more specific.
AK