See also:

Cylinder head - removal and refitting
Removal Note: On HCS engines, cylinder head bolts may be used a total of three times (including initial fit) and must be suitably marked to indicate each removal operation. A new cylinder head ga ...

Ford Sierra Service Manual
...

Crankshaft rear oil seal - renewal
Note: New flywheel/driveplate bolts must be used on refitting. 1 Remove the flywheel/driveplate and the engine adapter plate. 2 Extract the seal using an oil seal removal tool if available. It ma ...