All the credit for this goes to Peter Bates. The brackets supplied by Year One are a great product but come without instructions. Peter did his install and was kind enough to supply the instructions for us.
Peter Bates said: ↑
Sorry team I'm a E body guy but I thought I'd let you know Intel on this subject.

Seat relocation brackets bought from Year One.

These brackets in the front hole positions gave me nearly three inches more leg room. Great for a 6’4” guy. Wish I would have thought about this 20 yrs ago. Dang it.

Tools I used:

Dremel with milling bit
Drill with 3/8” drill
7/16” and 1/2” wrenches as well as deep well sockets.
small hammer
I bought new stainless steel bolts, lock washers, washers, and nuts to bolt in the seat to the floorboard. Get ones that are 3/8” longer than the original studs.

Step One:
remove the seat via the four ½” nuts below the car
once the seat is out on the floor I used the dremel to grind out the flared end of the studs on the tracks themselves. You cannot hammer them out as they are crimped into place. Once fairly ground down I tapped them out with the hammer.
Step Two:

place the seat on its side with the lever adjuster in the top position.
Remove the spring on the inside (the big one not the return spring for the lever)
Slide the rail forward that will expose the inside left 7/16” bolt. Remove the bolt.
Now you can slide the rail back farther that allows the internal bushing to come out. Note the orientation and location of the big roller bearing.
Remove the front 7/16” bolt and take off the entire rail
Slide the rail forward to remove the other internal bushing.
Clean it all up and slide the rails completely off the bracket.
The top rail rear portion will require a clearance “hole” for the head of the new stud, what I did was to install the new bracket with into position (front two holes in the forward direction) then mark the front hole on the rail itself. Remove the new bracket and drill into the sliding plate but not all the way through. I used the dremel to open the hole up enough to allow the head of the new stud to rest into it. Install the new bracket and stud onto the rail and align to be straight in line with the existing hole. Tighten as best you can, it’s a tight fit with the wrench.
Install the front new bracket with the holes toward the front of the seat. Tighten it up once aligned.
Grease the crap out of the tracks and assemble the reverse of the take down. Its pretty simple.
Install the rail but put in the front bolt first so you have room to use the deep well socket but don’t let the rail slide all the way off. Then install the rear bolt to the seat.
Install the spring.
Step Three:

Take off the other rail and tear down and clean as noted from above.
Install the front and rear new brackets. Hand tighten the bolts. The rear rail will need the 3/8” through hole drilled into it from the front hole of the new bracket (the new bracket hole is smaller so just rotate it out of the way once you mark the position of the front hole
Reassemble and grease her up
Install the rail back onto the seat and tighten the bolts.
Step Four:

Install the seat and wiggle things around a bit to get all the studs to plop through the holes in the floor board. Use locking washers and washers as required. Tighten it all up

Thank you,

Peter A. Bates
Principal Engineer - Innovation