Use skills: The key is accuracy and alignment.
As a first time user perhaps this will help you, this is the experience provided by an enthusiastic buyer:
1) Secure the watch strap in the gray plastic holder.
2) Use the hammer and the tips with the longer rod to tap the pin a little into the strap, enough so that there is a groove.
3) Move the watch into the vise tool. It should be much easier to align the tip into the groove.
4) Ensure pin on vise is straight and secure before you tighten.
5) Turn vise pin until you sink the tip all the way up to the base.
6) Turn vise pin the other way until the tip comes out clean.
7) Lift the watch off the vise to remove the pin. Use a set of needle nose pliers if pin still sticks.
8) Rinse and repeat for any additional pins you need to remove.
To put the pin back after removing a link:
1) First check if the pin got bent or spliced when you removed it, if necessary use a new pin.
2) Overlap links and insert pin until it fits into all openings.
3) Insert watch and strap into gray plastic holder.
4) Use plastic side of hammer to tap pin flush into strap so you don't damage or scratch the watch strap, especially if you miss.
5) Slap that beautiful newly adjusted strap on your watch like a champ and brag to anyone who will listen how perfectly it now fits.