I used a full 12" for my bracelet, that will give you enough tail to pull to tighten and to add a knot.
Slide on your slider first by gathering or folding the ends and push then through the hole, grasping the fabric with tweezers to get it pulled through if necessary and center.
Using the same technique as above pull an end through the antique silver slider tube.
Now run the other end of the fabric through the tube going in the opposite direction. Stretch the fabric over your finger to make more room. You may need to stuff it through with your tweezers careful not to damage the fabric.
Make an overhand knot in each end.
To wear, slip on your wrist and tighten the bracelet by pulling on the ends.