upgrade BH20 from v3.2.5

Products PMP
1

Does anyone know the correct upgrade procedure from v3.2.5 to v7.3.6 for a BH20?
I also need to corresponding software packages.

Any help would be greatly appreciated.

Thanks

2

3.2.5–>4.2.3–>6.1–>7.0–>7.2–>7.3.6