How to remove Junction Box to install OEM trailer wiring harness?

I recently purchased a 4 cylinder 2014 Tacoma Double Cab. I added the etrailer trailer hitch and I'm now in the process of installing the OEM trailer wiring. I was able to get behind the dash and remove the existing Flasher Assembly and install the new Flasher Assembly. However, I was stumped when it came to install the Flasher Assembly Sub Wire Harness (shown in pic below). I've read on TW that having Daytime Running Lights may make a difference so just to clarify my Tacoma does have DRL. I was hoping to get some advice before potentially screwing something up.

I believe I'm supposed to remove screws and wires that are holding the junction block in place so that I can access the rear of the junction block. Do I need to plug in all 4 wire harness connectors shown in the picture?

The 4 wire harness connectors from left to right in the pic are all male and are as follows:

1. 8-pin (the grey one)
2. 18-pin
3. 12-pin
4. 4-pin



1. Most importantly, how do I remove the various plastic connection pieces that are attaching wires to the junction block without breaking them?
caribe makaira mentions "the yellow arrows hold down the cable loom" and posted pics in this thread: https://www.tacomaworld.com/threads/need-help-with-lower-junction-box-in-cab-82730-04040.437337/
However, how do I get these fasteners off? Can I use a metal pry tool to get it off? I've googled and searched all over TW and I can't seem to find how to get them off.

2. Is there a free 8-pin female connector on the back of the junction block?

3. If I plug in the 18-pin from the pic into the Flasher Assembly, then I imagine I throw away the flasher assembly sub wire harness that was already installed?

4. Is there a free 12-pin female connector on the back of the junction block?

I found the wording from the instructions confusing. This is the exact wording from the instructions:

Page 9 of 30 instructions:

(3) Temporarily disconnect the 26-pin connector from the junction block.

(4) Disconnect flasher assembly sub wire harness 8-pin connector on the back of the junction block.

NOTE: Use jewelers screwdriver when removing the 8-pin connector.

(5) Disconnect flasher assembly sub wire harness retaining clip and 12-pin connector on the back of the junction. Discard the sub wire harness.

Page 12 of 30 instructions:

(f) Flasher assembly installation

(1) Connect the new flasher assembly sub wire harness 8-pin and 12-pin connectors to the plugs on the junction block and clip the retaining clip in place.

(2) Re-install the previously removed 26-pin connector.

Page 13 of 30 instructions:

(3) Attach the flasher assembly to the junction block using the two bolts (M6) [from step (j)(1) page 9] and tighten the two bolts.

(4) Connect the 18-pin connector of the flasher assembly sub wire harness to the flasher assembly.

(5) Install the junction block to original location.

In the picture below I have a loose 4-pin connector. I believe this is for the trailer wire that runs from this connection all the way to the rear 4 way trailer connector. Unfortunately, after I put in the new flasher assembly 81980-04050 and the relay, I connected the 4 way tow wiring to the 4-pin and it did not work. I'm assuming I have to install the new 4 wire harness in order for everything to work. Is this correct?

In the pic below, I circled on the left a black connection piece that I'm trying to remove. Should I force it off with a pry tool?

I don't want to screw anything up or break anything. Thank you for any tips or guidance.

 

In case anybody installs the OEM trailer wiring here's what I learned. To access the rear of the junction box you have to unscrew the various screws that are holding it in and you have to use a pry tool to remove the plastic brackets that are holding wires onto the junction box (it's what's in the circle on the left in the pic above).

Also, you need to remove the existing 3 wire harness and replace it with the new 4 wire harness. Here's a pic of the old 3 wire harness (82241-04050).

When you plug in the 4 wire harness, 3 of the 4 wires will plug in to where the 3 wire harness was previously plugged in and the 4th wire (which is the 4 pin harness) will plug into the harness I circled on the right in the pic. This harness then continues to the cowl side trim on the driver's side. Hidden behind the wires is the end of this harness. You plug the 4 way trailer connector wire into this harness and you're good to go! This was my first time attempting any sort of electrical modification and I was pretty nervous about bricking my truck! The Toyota instructions suck! I had to really research TW and google for answers. I hope this helps anybody else that wants to install the OEM trailer wiring harness.