electric antena mast on 2003 Lexus SC430

my antena will not go all the way down when radio is off. bought a new mast, what steps should I take to replace old for new

Asked by for the 2003 Lexus SC430
The Lexus radio mast has a chrome colored ring around the base of the antenna mast (there is a tool to remove this ring to avoid scratching the the bodywork but I have loosened the locking ring with two screw drivers and a lot of care). With the locking ring removed get someone to turn on the radio while you pull upward on the antenna mast/cable. Compare the length of the "new cable and mast" with what you have with drawn from the motor. If the new assembly is longer a piece of the old cable is still stuck in the motor assemble and it must be removed and dissembled to remove the entire cable or you will never get the antenna to fully retract. If you are lucky enough to have gotten all the cable out to get the new cable to retract. Feed the cable into the motor until you feel it engage the gear in the motor, get a friend to turn off the radio and the cable will retract. If it doesn't fully retract, turn the radio on, let the cable and mast fully extend wait a few seconds and then retry turning of the radio. Probably half the times I end up having to take the assembly apart to get out pieces of broken cable, not a job I think you would want to tackle.
as much as I do NOT want to tackle this project, economy tells me I have to. My question is taking off the trunk liner to gain access to the antenna works. Any suggestions?
Thanks for your time
2 more answers
Your local body shop will give your an estimate to change the mast, Its common to damage the antenna when involved in a collision, It takes a experienced mechanic to change a mast because the electric motor has a tractor drive system.
how do I replace the antenna on my 2002 430