how to change controls on Spektrum DX6i?

[caterpillar]

Does someone know how to change the functions of the controls on a Spektrum DX6i in 2 different modes?
I found this picture (not sure who it is from) but it seems to be possible on a DX5e so it must be possible on the DX6i one would thinks so.



So in excavator mode the controls shall have a different function than in driving mode.

if anyone knows how to configure that, pls let me know.