Camshafts and camshaft adjusters, removing and installing: All:

Unbolt Hall sensor housing (10 Nm).
Remove bolt securing Hall sensor rotor (20 Nm) and carefully pry off rotor using a screwdriver.
Insert camshaft clamp 3391 in the securing plates of two camshafts.
Loosen both camshaft bolts and remove approx. 5 turns.
Take out camshaft clamp 3391.
Disconnect both camshaft sprockets with special tool T40001.
Using a screwdriver, carefully lever oil feed lines for camshaft bearings out of camshaft bearings.

Make sure that the retaining catches do not break off when prying out the oil lines.

Fig 1: Disconnecting Camshaft Sprockets

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NOTE: Do not over-tighten retainer for chain tensioner, otherwise camshaft adjuster can be damaged.

Fig 2: Securing Camshaft Adjuster Using Retainer For Chain Tensioner 3366

Courtesy of AUDI OF AMERICA, INC.

NOTE: The two markings on the camshafts must be in line with the two arrows on the bearing caps.

Clean drive chain and camshaft chain sprockets in vicinity of arrows on bearing caps and mark position of chain on sprockets with paint opposite two arrows.

Fig 3: Identifying TDC Position Of Camshafts

Courtesy of AUDI OF AMERICA, INC.

NOTE:

The distance between the two arrows (and thus between the paint markings) is 16 rollers on the chain.
The notch on the exhaust camshaft is offset slightly towards the inside in relation to chain roller -1-.
Do not mark the chain with a center punch or by making a notch or similar.

Fig 4: Identifying Distance Between Camshaft Drive Chain Paint Marks

Courtesy of AUDI OF AMERICA, INC.

Remove bolts securing camshaft adjuster -6-. See Fig 5.
Remove bearing caps 1, 3, 5 and 7 from inlet and exhaust camshafts and place them in correct order on a clean surface.
Loosen bearing caps 2 and 4 alternately and in diagonal sequence, and remove from both camshafts.
Take out both camshafts together with camshaft adjuster.

Fig 5: Removing Camshaft Adjuster And Camshafts

Courtesy of AUDI OF AMERICA, INC.