Raymarine E120s (2) Classics and RS 125 Antenna issue

[C Skip R]

My RS125 antenna is going bad. I decided to replace to find out RM doesn't make that model any longer. Have to install RS130 and also need a special coupler E22158 according to RM techs.

Does anyone have experience making this conversion. Assuming I will have to remove old antenna and cable. The boat is a sportfish flybridge so going to have to pull new cable through flybridge tubing. Pain in arse.

I have two E120s with one being the master. There is a Seatalk connection bar with 3 connections. One from existing antenna, I think one to other E120 unit and maybe one to the nema 0183 terminal bar. Not positive on this.

Now what is the next step?