The procedure essentially involves:

1) Removing the spark plugs and valve covers;
2) Placing a 27mm socket on the nut that's deep in the crankshaft hub;
3) Using that nut to rotate the hub's markings from 0 through 90, 180, and 270 degrees, causing the various cylinder pairs to reach top dead center;
4) Inserting rope or a spark plug adapter on an air compressor into each of those cylinders to keep their valves from falling;
5) Removing each cylinder's rockers
6) Compressing each valve spring with an "on engine, over-head cam valve spring compressor", which has a hook to grasp the camshaft;
7) Using a magnet to remove the valve spring's keepers;
8) Removing the springs and their covers;
8) Prying the old seals off;
9) Carefully installing the new seals, so as not to damage them; and
10) Reinstalling the springs and keepers.

Although this might sound fairly easy and straight forward, the job can be quite difficult, especially if you don't have the compressor MB specifically designed for the job, as putting the keepers back on can be a real PITA. KD makes a similar compressor, but having used both, I can safely say that the job is far more difficult using it, rather than the MB version.

If you've never done anything like this before, considering the cost of having an Indy do it for, say, $400-500, I'd recommend that rather than doing it yourself.