I've done a couple, but not on the 603. Yet.

Here's what to do.

Remove the head.

Buy valve guides
Buy intake valves
Buy exhaust valves
Buy valve guide seals

Take the head to a machine shop, with the parts.

Pick up completed head a week later.

See. DIY is not at all that hard.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)