Pascal,
Check out this
1941 Car & Truck Shop Manual resource document for your 1946 AK as it covers 1941-46 trucks and provides details on your ring and pinion change out.
Section 4 (starting on Page 86) covers your truck as the car and 1/2 ton truck rear axles use the same steps for service/repair, except for the minor difference listed on Page 93.
Looking forward to seeing and hearing more on your project.

Dan