I would like to find out how to get the spool piece out but I don't know how to get it off trimmer.

thomas steinberg, May 2008

to replace the trimmer line on an IDC 540, remove the "bump head" by turning it counter-clockwise while pressing down on the line spool. It may be very difficult to loosen due to dirt buildup, but it will come off and the line spool can be replaced or refilled.

Julie Peck, June 2008