Thinking of replacing 2 HD boxes with a Genie and client. That will leave me with 2 HD DVRs and a Genie on my current SWM 8. Is it just a matter of swapping out the 4 port SWM 8 with a SWM 16 SWM. No new cables needed since receiver count and location staying the same? Will DirecTv allow this as a self install?