To elaborate just a little bit on the FAQ... you may or may not have to remove the sled. It will depend on whether you can get access to some of the wires behind the sled -- specifically, the connector on the sled harness that attaches to the tuner; and the antenna lead that used to be connected to your radio before you replaced it with the empeg.
Even if you have access to these two connectors, you still may have to remove the sled if you have no other way of physically getting the tuner into a position where the connectors can be attached to the tuner. One possibility is that the tuner is (just) small enough to go in through the front opening of the sled and out the bottom opening, so you may find enough room there.
One thing I have learned from experience as a mechanic: It is usually easier to take a little bit more apart to gain access to what you are working on than it is to try and fight it. In other words, disconnect the exhaust pipe so you can get to the starter rather than try and get a wrench in there that will only make 1/12 of a turn at a time. Same thing applies to the empeg sled -- if you can't get the tuner in there easily, pull the sled. It's less work than you might think, and you can take the opportunity to give a good tug on the wires of the sled connector to make sure you don't have one of the early sleds that were prone to having the wires come loose.
tanstaafl.
"There Ain't No Such Thing As A Free Lunch"
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"There Ain't No Such Thing As A Free Lunch"