Have an Intertherm gas furnace, has 5 burners, two will not ignite, have cleaned all areas but do not know how to remove the actual burners to clean, have no manual or directions...

The best thing to do is try and locate a manual online. There is the possibility that the orifices for the burners that won't light are clogged. Is it LP or Natural Gas. LP is inherently dirty so if the furnace is LP, the orifices are probably clogged or blocked.

The burners have a screw on each side of each burner that will have to be removed to get the burners out. The ends of the burners will need to be cleaned. Clean the cross overs and remove all rust(ears of the burners). Make note of witch burner goes where because the end burners may have a crimped end on one side of the cross over.