I never had to tackle with it , but here what my repair manual says;
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SECTION 303-01B: Engine — 6.8L 2000 F-Super Duty 250-550/Excursion/F-53 Motorhome Chassis Workshop Manual
IN-VEHICLE REPAIR Procedure revision date: 06/21/1999

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Oil Level Indicator and Tube
Removal

Remove the engine air cleaner (ACL) (9600) and the air cleaner outlet tube (9B659); refer to Section 303-12.
Remove the left exhaust manifold (9430); refer to Exhaust Manifold—LH in this section.
Remove the bolt and remove the oil level indicator tube (6754).

Inspect the oil level indicator tube for damage.
Installation

To install, reverse the removal procedure.

Replace and lubricate the O-ring seals with Super Premium SAE 5W-30 Motor Oil XO-5W30-QSP or equivalent meeting Ford specification WSS-M2C153-G.
Install the left exhaust manifold; refer to Exhaust Manifold—LH in this section.

Good luck.
Ken