Not many 350's over here, but assuming the same basic SOHC design, the seal replacement needs the following tools:

- valve spring compressor (the ones that hook under the cam work well)
- air compressor
- air fitting for spark plug hole
- remote starter switch

The sequence is as follows for each cylinder:

Remove spark plug
Crank engine so valves are closed
Compress the valve spring and remove rocker arm and "hockey puck" pad. If you can't compress the valve enough because it hits the piston, turn the engine a bit more.
Introduce compressed air through the spark plug hole to support the valves
Compress the spring again and remove the collets (sort of little half-round wedges) with needle nose pliers or a magnet. Remove the retainer, spring, and the old seal.
Put a bit of oil of the valve stem and slide the little plastic protector that comes with the seals over the notch in the stem
Slide the new valve seal onto the stem and press it firmly against the head
Remove protector
Reinstall spring, retainer, and collets
Remove air supply
Reinstall hockey puck and rocker arm

At the end, reinstall the plugs, and button up everything else and you should be good to go

I predict it will take you 20 minutes to do the first, and 2 minutes to do the last.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe