I am having an issue with repairing my engineered hardwood floor.

The layout of my floor is as such, I have three sections of flooring I need replaced indicated in red, planks 1,2, & 3. The flooring had some holes drilled into it from an old aquarium that sat near there and the plumbing was piped into the basement. I have since sold the aquarium and need those specific planks replaced now.

The flooring despite how my MS paint looks, is all identical widths, but varying lengths to give the floor a random look. So ignore the fact that my drawing is out of whack please. They slot together tongue and groove style and were nailed into the floor. Looked like an easy DIY repair. Ugh.

Now, the old sections have been removed as well as the baseboard and the replacement flooring I have I thought would just slide in and I figured it would be an easy job. Well looks like I was wrong.

The replacement flooring looks identical, and is the proper lengths, but the planks are too wide. Just barely. It is too wide by about 1/16ths of an inch. But it is enough the throw everything out of whack. The entire box is too wide. I tried every piece and they are all like this.

Now, a bit of back story, When I originally bought this house (I bought a brand new house) I had the home builder get me two boxes of replacement flooring when I first had the house built just for situations like this so I wouldn't have to go hunting down the replacement flooring in case it was discontinued or something in a few years. Now I haven't touched the boxes in over a year (the house is only a 18 months old) They did however sit in my unfinished basement for the past 18 months on the floor.

Ok, so number 2's width doesn't really matter, the extra 16th of an inch hides under the baseboard and wall so it doesn't really cause much of an issue, but because 1 and 2 "straddle" number 3, they are both pushed "higher" and there is a gap where 1 and 2 overlap onto the planks in front and behind 3 (planks 4 and 5) indicated in white.

Also because 1 is too wide and because of 3 pushing it higher, it REALLY doesn't fit in on the left side between planks 4 and 6.

The home builder has been less than helpful to this point, so I am wondering what the best solution is here? I just need the floor fixed at this point, is there something I can do easily to get the planks shaved down to size properly?

If the manufacturer of your flooring indicates that it should be acclimated prior to installation then you could try to reacclimatize the new pieces to lower its moisture content and hopefully shrink it. Also, maybe shave the tongues on #1 and #3. New house unfinished basement (concrete walls?)....what part of the country?......high mc area.....not a good place to store wood.

yes, poor choice in where to store the flooring. I had no idea not to store it there.

That being said what is done is done now so I am left salvaging what I can here.

The tongues are not the issue. I have laid the pieces side by side, (old and new) and the walking surface is the simply wider, so shaving the tongues will do nothing.

Is there a way to "shrink" the wood easily? I have left a few slats in my office for a few weeks now to attempt to get it acclimated back to what it should be, but is the damage to the wood already done? Can it be reversed?

My house is in Canada, Ontario Canada to be exact.about two hours from the border.

Put it in an area with low humidity. Lowering its moisture content should cause it to shrink.

Put the board next to a heater vent. The warmth will drive the moisture out.
It may not completely shrink back to the beginning size. You may need to plane the groove side a little. The best thing to do is use a moisture meter to make sure the moisture has left after you help it to dry some.
Its better to store flooring in the attic than in an unheated basement.