Yes, you'll need to replace at least a section of that aft spar, in accordance with what Vans says. Also, you should check edge distance on the hole in the clevis - the part where this part attaches to the fuselage. If the edge distance is less than 5/8", you'll need to replace that part too.

Bought new parts, hired a good sheet metal man to do the repairs. That was before I had the skills to attempt it myself.

Those pieces can be replaced without removing the spar. As mentioned you can drill out enough wing root rivets on the bottom skin to gain access to buck rivets or you can cut a couple of access holes in the bottom skin. Covers can then be riveted over the access holes with structural pulled rivets.

I know the second option works because it was done several years ago on an RV-6 with which I am very familiar. ;)

However....you need to be proficient with RV-type construction techniques or get someone who is to do the repair.

Before you got tearing into a set of wings, you may want to have a DER or aerospace engineer take a look at it. There may be an on-wing repair you can do.

I found some bonus holes in the stab on my -8 when I got it, and the Van's tech rep was pretty quick to pull the "replace" trigger. I don't blame them. There is little value for them in investing the engineering on a possible repair for a one-off issue, not to mention the risk vs. something that is known to work.

But for you there might be a lot of value in not having to drill out a bunch of rivets (which has it's own risks), wreck paint, etc....

DEM

Rear Spar
 

I can help guide you if you are still looking for help. PM me and we can talk in more detail. I'm very experienced with all the Vans models including the 6.

Ryan