Dan,
I am assuming the 2400 is pretty much the same as the 2200.
To clean the rollers put a sheet of plain paper in the sheet feeder, wet with alcohol or Windex about three inches wide all the way across the sheet. Use the paper feed button to run this through the printer. Repeat with clean sheets until they come out clean.
If it is from buildup on the print head here is my method. I use strips of paper towel cut, not torn, about 1 1/2 inches wide, folded in 1/3s to about 1/2 inch wide. I work them under the print head, put a few drops of Windex on the towel until wet but not dripping. I slide this back and forth pullling gently against the surface of the print head. I repeat this until they come out fairly clean, then repeat with dry strips a couple of times. print some nozzle checks and you should be good to go.
Also, while the print head is moved off the park position, use a long Q tip and Windex or distilled water to clean the o-ring on the capping station. Sometimes paper fibers and in my case kitty hair can keep it from sealing properly.
HTH
Rich