I have a Legency comand system,its in cab 1 mood,how do i get it to cab 2 mood.

If you have a legacy engine load the engine module that came with it.
If you have only TMCC engine, load the generic steam or diesel module that came with the legacy set.

Ok ill try that thank you for the reply.

During the setup of the engine you can set it to whatever mode you want it in, (if you do not have the generic modules) On some non-Lionel engines you may have to select CAB1 instead of TMCC (1)

The manual covers this pretty well

Thank you very much for the post,i been having problems ,maybe my dash-9 chip is bad dont seem to want to do anything when i hit the down load button..

The chip are not required to load an engine into legacy, its just a convenience. All the setting can be made on the handset, just go through the steps in the manual.