Yes easiest bet is just buy a disc to disc open centre, put the locker in while it's on a bench, then just swap diffs.

you could do it yourself if you can swing a spanner. There is nothing overly involved like re-shimming etc I believe.

thanks man. i might just change centres instead of a whole diff. its in a ute. fairly straight forward. do you know where to get the gears i need from?