2w900fmr cm3000

I've got the entire system up and running, two questions,

1) need to get a new remote to work, I have bought the replacement remote but can't get the system to pick it up?  any advice?

2) Adding to the Aux buttons, how do i get them to work, do i need to use them as the (-) of the circut?  just would like some clarification before i Start to add things.  any help would be great.  Thanks.

thanks!  one down!

would like to get the Aux done too, but don't quite understand the wiring of it.