You can't higher the presser bar lifter but you can higher the presser bar itself, you will see the screw partway down the bar but if you higher the bar for incredibly thick fabric you will need to lower it again for thinner fabrics, be very careful because the presser bar is set for the thickness of fabric it is designed to take, if you make the machine sew a thickness of fabric is is not set for you may find yourself with large repair bills.
ken, November 2011