Have them move the links from the front holes to the rear holes on the torsion bars, both front and rear axles.
Regarding the Front torsion bar:
On your front, you may have whats called "Z" brackets. They may need to be completely removed as they will hit the link if they try to re-use them. It will be very obvious. They won't be able to re-mount them.
The drawings below show what you currently have, what it will look like after you do the CHF, and what it would look like if you extend the links by 2 inches.
Regarding the Rear torsion bar:
You may have a version of a "Z" bracket on the rear, these may need to be reversed and re-mounted. "Z" brackets are not a problem on the rear.
IMPORTANT - Inspect very carefully the torsion bar attachments and bushing to the axle. There seems to be a great deal of reports that the rear ones have problems with loses bolts and broken clamps.
I attached drawings from what I posted on a different site.
The link below is how I performed the CHF on mine, PLUS how I modified my standard links to make them 2 inches longer. There are some good before/after of the torsion bars, etc
Your F53 will be a little different than mine.