All 12 valves are disassembled the same way.
If lifting bracket is not damaged or cylinder head is not being replaced, do not remove lifting bracket.
(1) Remove two screws (1) and lifting bracket (2) from cylinder head (3).
(2) Remove seven pipe plugs (4,5, and 6).
(3) Disassemble each valve as follows:
(a) Disassemble and remove two valve collets (7), spring retainer (8), spring (9), and stem seal (10).
Discard valve collets and stem seal.
(b) Tag and mark valve (11) to identify position. Also label a rack or piece of cardboard.
(c) Remove valve (11) and place in rack or cardboard according to mark.
(4) If damaged, remove five expansion plugs (12).