Can anyone state the correct procedure for removing the stock shift knob for the 1995 Mercedes 420? I have purchased a replacement from a private party and would like to do it myself. The replacement shift knob is threaded. I tried to unscrew the stock shifter but it is either not threaded or perhaps there is a certain procedure that must be performed in order to remove it. Can anyone say if it is possible to do without the help of a mechanic or tech? Any input would be appreciated. Thanks in advance.