Now the problem is if you remove the valve locks and the retainer now, the valve will drop into the combustion chamber, and you'll need to take the head off to get it back. I'm choosing, if you've not guessed already, to use as someone eloquently put it "the rope trick".
To do this what you need to do is set the cylinder you're working on to somewhere round about bottom dead centre. It doesn't have to be too precise.
To do this it's easiest if you remove the spark plug, if you haven't done it already when setting up the timing marks earlier on. (You'll need a 16mm spark plug socket to remove the spark plugs)
To find approximately bottom dead centre (BDC) I gently put a long (maybe about 9 inches or more) screw driver down the spark plug hole, and then turned the crankshaft untill the screwdriver stopped moving down and started to move back upwards. Here's a pic of it st approximately BDC:-
Remove the screwdriver once you're at BDC.
Now tie a knot into the end of the rope you've bought, and then start to feed it all into the combustion chamber through the spark plug hole.
Now turn the crank shaft gently untill it you feel resistance. This is the rope being compressed between the top of the piston and the bottom of the head and the valves. This will then stop the valves from dropping into the combustion chamber when you remove the locks and retainers. Genius.
So now you'll be ready to remove the locks and retainers. You'll be using the valve tool to do this. However I found that the diameter was slightly too large, so I placed a washer onto the end of it (it's got a strong magnet inside it by the way - this is what "grabs" the valve locks) Also now's a very good point to take some paper towel and place it anywhere where any small parts could fall down. In particular the oilways between the valves.
You then simply place it against the retainer, and give it a medium tap with a hammer:-
The valve spring compreses, and the retainer moves down the valve with it. However the valves not moving, which means there's no load on the valve locks, and the magnet in the tool whips them out the way. When the spring un-compreses, there's no locks to hold the valve retainer in place any more, so the retainer becomes free as-well. (And incidentally get's grabbed by the magent also)
Here's some pics of the locks and retainer:-
Here's a pic of the valve tool with the locks and the washer stuck to the magenet:-
valve locks - yes they are that small!
You can then just lift the valve spring out. I marked it so as I knew which way up it cam out:-
So now it was possible to remove the actual valve seals using the valve stem seal pliers. The inlet side was quite difficult to pull out, but after a good pull it finally pried free.
Unfortunately I just had enough time to remove 1 to take a pic for you, sorry about the quality, I'll take some better ones tomorrow when I do the others and get a couple of shots of what they look like before they're removed.