I replaced the antenna mast in my 92 LS400 with a $20.00 unit I bought from ebay. Very easy:
1) Turn ignition to "lock"
2) Remove the round slotted nut on top of the antenna (the antenna nut)
3) Have an assistant hold the "AM", "LW/MW" or "LW/SW" and ( "CD" or "TAPE" )butttons in while simultaneously turning the ignition to "ACC"
(The mast will extend fully, pushing the toothed nylon cable out as well...guide it so it does not scratch the car and use a towel...it is very greasy!. If it does not all come out, you will have to remove the antenna unit itself and take it apart to get the pieces of the nylon cable out...still worth doing!).
4) Once the old mast and slotted cable are out, be sure the ignition is still set to "ACC" and the radio has been turned on using the procedure in step 3.
5) Insert the new mast/cable into the antenna hole with the slotted teeth in the cable facing toward the rear of the car. ( the manual says push it in 400 mm )
6) Have an assistant turn the ingition to "LOCK"...the cable, then the mast should be drawn into the hole while you guide it.
7) Even if it has not been drawn completely in, reinstall the antenna nut. The mast will eventually adjust itself and extend/withdraw competely.
8) That's it...cheaper than having the dealer do it by a long shot! ... Good Luck
