Next we'll use a valve spring compressor to get spring and retainers off of the valve. Funji has some great advice about giving the spring a good whack before trying to remove it. This loosens the keepers so they'll come out much easier. Once compressed the keepers will come out from the top and the spring can come free.
Here we have the compressed spring and the two keepers easily visible. Now it would be very easy to remove the valve stem seals on all 12 valves one by one. Installation is the reverse of removal. For more info about changing out the valve stem seals, check the project by Funji where the explains the process in much great detail with the cylinder head off of the car.
Yes this may seem very ghetto but it is a proven old trick without having to break the head seal. Set aside some time to get it done and you too can have fresh stem seals and solve the oil loss and colored exhaust that all of us get as these cars age. Thanks.