the directions mustangworld has are correct for which wires to splice...you just take a really sharp knife and take off about 1/4inch of the wire's covering...match up the correct wires (should say on the line convertor as well as from mustangworld)..
remote wire i just put through a switch directly to the battery because its the easiest....i should have a fuse in the line too, but havent gotten around to that yet...
i grounded on a bolt in my trunk...its up underneath the rear speaker's panel...should be able to find one if you pull out the "carpet" that covers the spare...
its not too hard, but splice the wire's covers off takes a lot of patience and time if you arent careful....i wouldnt suggest cutting them and connecting them all together though, because they dont leave much excess wire...its all farily tense...and triplecheck the wires before you strip em..
btw...you wont be able to use wire caps (those things you screw on bare wires) because you dont have enough loose wire...so use some good electrical tape and wrap it around a few times...