2007 V50 2.4i front seatbelts removal help

[dudeitssm]

Greetings.

I'm trying to remove and replace the front seatbelts on a 2007 V50 2.4i.
This car shares many parts between 2005 thru 2011 models, including seatbelts, airbags, doors, fenders, etc.

There are one or two things preventing me from replacing the front seatbelts...

The main issue is there appears to be a "rivet" of some sort (imprinted with a "cross" or "x" shape).
It runs through the latch. I'm attaching a few pictures below to show what I mean.

If I can't get the rivet out, can I instead use a T47 (or I think it's a T47 torx bit) to unbolt the entire assembly instead?
For the record, I'm having both seatbelts rebuilt by a seatbelt restoration company.

Here's an eBay listing showing just the latch, circled in red, without the rivet in it.
Somehow, this person managed to get the seatbelt out. I want to know _how_?

There is a green connector, circled in yellow, that I am curious about. Here are my questions:

1. How do I remove the rivet?
(I was thinking of using a dremel to shave it off carefully on one side, then knock it out with a screwdriver).

2. How do I replace the rivet? I probably need a special tool.
(Failing that, my alternative would be to use a nut and pan head screw in place of the rivet).

3. What is the green connector, circled in yellow, used for? It appears to be sensor related, as opposed to the other two connectors, which trigger two separate pyro charges.

Thank you for any pointers.