Essential Tools:
Sharp scissors, spring bar tool, soft & flat surface. 

Step-by-Step Guide:
Step 1. Mark & Measure
- Fit the lug ends (with quick release spring bars) of the straps to your watch.
- Place your watch face down on a soft & flat surface.
- Rest your wrist against the watch case back, with your palm facing up. 
- Fold the strap over your wrist to estimate the excess length you need to remove.

Step 2. Trim the Strap
- At the tail end, you will find repeated segments of grooves and spring bar holes.
- Cut along the groove to trim the strap. 
- Be conservative in the estimation to avoid over-cutting.
- Loose initial fit is preferable to a perfect fit on the first try.

Step 3. Fitting the Clasp
- Install tail ends of the straps to the clasp using the provided spring bars. 
- You might need to use a spring bar tool for this process. 
- Ensure all ends are secure before wearing the watch. 

Step 4: Check the Fit
- If the fit is too loose, repeat Step 2. 
- In the final stages of getting the right fit, remove a segment at a time.

Important Tips:
Cut Conservatively - Start with smaller cuts and gradually adjust as needed.
Quality Tools Matter -  Use sharp scissors to make clean cuts.
Patience is Key - Take your time to avoid accidental over-cutting.
Asymmetrical Cuts - Number of segments on both straps need not be the same.

You might find the fit to be more comfortable with the top strap having an additional segment.