To remove

Remove the power train, see POWER TRAIN
Zero the engine by turning the crankshaft in the engine's direction of rotation until the timing marks on the pulley and timing cover are aligned.

Fig 1: Illustration For Steps 2-3
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Remove the crankshaft pulley.
Remove the timing cover (not cylinder head) See TIMING COVER
Remove the top chain guide and chain tensioner for the balancer-shaft chain.

Fig 2: Illustration For Steps 5, 7, 8 & 9
Courtesy of SAAB-SCANIA OF AMERICA, INC.
Remove the pivoted balancer shaft chain guide.
Remove the idler sprocket and balancer shaft chain.
Check that the sprockets and chain guides are in good condition. Don't forget to check the fixed chain guide that is common to the timing and balancer shaft chains. Change any parts as necessary. Observe that the balancer shaft sprockets are different.
Tightening torque, balancer shaft sprocket 25 Nm (18 lbf ft)

Tightening torque, fixed guide for timing and balancer shaft chains 10 Nm (7 lbf ft)
Remove the sprockets from the balancer shafts.