I have a 2000 softail springer. The other day I was riding and stopped the bike. When I went to re-start the bike , all I heard was a squelling , spinning sound. The bike would not even turn over. I had to push start it. Could it be the starter or solinoid ? Are they easy to change ?

Your 2000 model bike has a starter made by Nippondenso and the starter and solenoid are unitized. Your problem is what is known as the "over running clutch" and it has gone bad. It is a replaceable unit but it requires not only the removal of the starter but disassembly of the starter as well. If you can do the work yourself, you can save some money by replacing the clutch. If you can't do the work, just have the entire starter replaced. The labor time involved in disassembling and reassembling the starter will eat up any savings you might have realized by replacing the clutch rather than the entire starter. It takes about an hour to disassemble the starter and replace the clutch after you've got the starter off the bike.

Good Luck
Steve