Assuming your post is a request for "how to do it" here are the instructions I wrote for myself based on the Massoth instructions (not the clearest) and advice from my dealer:
The key bit of input from my dealer was the "Always read first" before changing. Hope this is what you wanted. Others may have other tips and tricks.
Decoder programming with Massoth Navigator - General
Step Key Menu item
1 M3 M3 key for MENU
2 M1 Cursor moves down 1 step to Decoder Progr.
3 M2 OK Loco Address
4 M2 OK To select Loco Address sub-menu; cursor moves down to Address
5 M1 CV→ reads address, speed steps, direction and digital/analogue
6 M1 Goes to CV Read + Prog. Menu
7 M2 OK drops to CV number
Enter value of CV to be read
ALWAYS READ FIRST!!
8 M2 OK OK to confirm; cursor moves to value
Either
9 M1 CV→ reads CV value
Or
10 Enter new value; shows binary equivalent below
11 M2 OK OK to confirm change; tick appears by new value if OK
12 M3 To exit back to driving mode