You need to soak and cap the heads until you get new parts. Close off the 6 cap lines with binder clips, fill the caps brimming full with cleaning solution and lock the print heads in place. Start up in service mode and go directly into the service menu and down to CAP&WIPER CTRL, where you can close the caps. Don't turn off the printer from the sub power, as it may go through a shutdown sequence and give you an error. Instead, power it off in the back and unplug it. Here are the part numbers you need... If you can't find the parts, message me, Roland has them in stock in California. That video should be just fine for replacing the parts.
Pulley - 21975154 - PULLEY,UD49.2S4(B4.6C6.6)
Cable - 21945144 - WIRE FJ-540