How do I remove the springs from the exhaust valve? and not removing the head.? I have spring compression tool. compresses the spring but the top retaining ring does not slide down. I assume it's suppose to slide down to remove the retaining clips, then the springs can be removed? The tool has 2claws to the bottom, and 2 flanges that goes on the retainer ring. Should I just keep turning until the retainer ring slides? ( I only did a little but the retaining ring did not move, only the spring compressed a bit.)

Before you do anything , make sure you put air in the cylinder. if you dont and you remove the keepers, the valve can easily drop into the cylinder forcing you to take the head off.
So after you get air in the cylinder, compress the spring with the retainer as an assembly with your compressor tool, then simply remove the 2 keepers. Be careful not to drop them down an oil or pushrod hole in the head.
Why are you replacing the springs?

Old school ,fool proof way to make sure a valve doesn't drop while compressing spring is about 3/4 way up to tdc on the cylinder you are doing ,feed some 1/4"(or so)braided line into plug hole .Then continue to turn towards tdc until line is compressed up against valves .Changes springs ,then reverse rotation and bring piston back down. Pull out line

I have surgical clamp holding the shaft of the valve. It will not drop down, but I need info of removing the spring. Al the ports in the heads are "plugged" nothing will drop down. Do I just keep compressing the spring, with the top round retainer as a unit? how do I get access to the small clips. It almost seems that I have to compress the springs "under " the top round part.

AS I compress the spring it compress, but the top round plate does not move.

How are you holding the stem and trying to compress at the same time, Unless it's the small bit above the keepers

Compress the cylinder with air, and get one of these to compress the spring, and a magnet tool to remove the keepers. Its sounds like your using the crank down style spring compressor (sorry forget what they call them)

http://www.alltradetools.com/catalog...ompressor.html

I am using a crank type compressor. On the 525, there is virtually no space or gap between the shaft, where the rocker arms sits and the round plate. so where is the 2 peace retainer clips? and what part do I compress. if I try to compress the springs with the round top plate the plate does not move.

I have a long clamp into the exhaust port holding the valve shaft from the inside of the exhaust port.

You can take a deep socket that is slightly smaller in diameter than the retainer and hit the socket gently with a hammer while holding the socket on the retainer. This will loosen the keepers so the retainer will move when you compress the spring. Don't hit it too hard or the keepers may pop out.

I saw that on youtube, but I was afraid to hit it. I will try in the AM.. Thx.