04 altima shifter

[Phantomdragon]

i had a question about changing the shift knob. i was originally gonna get a short shifter, but they can get pricy plus install, not sure if it's worth it (as i'm not racing with the car). i would like to change the boot (as a few cracks in the leather) and the shift knob (foam ripping) to a nismo one. i know how to get the boot loose, but my problem is getting the shift knob off. is there any special technique in taking it off?? will the original knob have to be ruined to remove it? and how would the new boot be changed as well. also has anyone thought of making a gated shifter for the manual transmission?? (kinda how you would see on a ferrari)

thanks