Lay the shower curtain flat on a table. Fold 2 inches of the top edge down toward the inside. Fuse them together with a strip of fusible seam fabric and an iron, following the instructions on the packaging. Cover the fabric with a towel if it is made of polyester, to keep the iron from melting it.
Mark where you want to place the grommets on the fabric. Measure the width of the shower curtain and divide by 6 to find how many grommets you need to install -- they should be spaced every 6 inches.
Turn the white platform in the middle of the pliers so that the small end is in the front. Position the pliers over a marked grommet position on the fabric and squeeze the pliers firmly to make a hole through the fabric. If the fabric is too thick, use a pair of sharp-pointed scissors.
Switch the white platform around so the larger end is facing forward. Place the grommet through the hole from the table-side of the fabric. Lay the washer end of the grommet on top of it. Position the pliers over the bottom and top of the grommet and squeeze hard. The pressure will force the grommet together.
Repeat for each of the holes.