removing and fitting gear knob on a fiat punto mk1

I am wanting to change the gear knob in my mk1 fiat punto, however this doesn't look like an easy job. I have read a number of posts stating
that a knife and hacksaw is to be used. i for one am very nervous about taking a saw to my gear knob since knowing me i would probably mess up. could someone explain this proceedure to me as i would be most grateful. in addition would i be correct in saying a new gaiter would be required for this job, since it is this it seems i would need to cut through. I have had a new gear knob sat in my room for some time now, but after reading a few post i am temped to buy a new one which comes with a gaiter. Any kind of feedback would be most appreciated Thanks
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