where the 469 is in base 10.
Now to convert 469 to base 7. The largest power of 7 that divides 469 (without being larger than it) is 3:
The next largest power of 7 is 2:
The next largest power of 7 is 1:
And the last power of 7 is 0:
I would not be surprised to find that the Euclidean Algorithm provides a way to do this directly from base 8 to base 7, but I don't know how to set it up.