We did it outside the car with the box dismounted. The box comes in & out easily. All my comments have been from reading & the scribes have been known to get things wrong before (other than my own car experience & 2 donors). The OP should be concerned or you could end up with a mess that steers badly. Scrubs it's front tyres & does not give all the benefits of the Varamatic system which was the best of the 4 options of Manual, PAS First type, PAS Second type & PAS Bendix Marles Varamatic, made under license from Bendix by Adwest.

The Varamatic operates on a very specific curve that matches slip angle.

When the input shaft seal had a minor drip ~ damage done by the rebuilders. We all know about seal damage on the splines if precautions are not taken. My mechanic had the steering box out of the car in 15 minutes for seal replacement. I sat & watched him. The rebuilders replaced the seal FOC with an apology. We popped the box back into the car in an equally short time and that's as it is now sans leak.

 

I will have to climb under the car tomorrow to remind myself of the room I had to work in but as far as I can remember it was not hard, I just lifted the Tie Rod end up and lowered it into the hole in the steering arm. I say this as I cannot remember struggling to get it to fit, cursing at the damn thing, hitting it with a hammer or having to lever things out of the way.
This is the Tie rod end I used from SNG Barrett. It comes as one and you just screw the threaded end into the cross piece and lower both the pin on the tie rod into place and then push the pin from the steering arm into its hole before doing up the nuts.

Even thinking back to when I removed my steering box several years ago now to replace the seals I did not remove any of the steering arms. I simply released the Tie rod end from the steering box arm and lifted it away. When the steering box was replaced I put the box in first with the steering box arm attached and then fitted the Tie rod to the arm before doing up the nut. Again no issues as I recall.

If you have a specific problem which you can show in a photo it might help us to determine what is wrong and suggest an answer.

https://www.sngbarratt.com/English/#...or%20%60c29%60

 

We had an equally painless experience Rob installing the PTFE pins in place of the Metalastic variety. Yes I have a highly capable & skilled helper from rebuilding Auto boxes & Overdrives to spray painting. The best I have experienced. A 35 year old that stutters. Tall & skinny with the strength of an ox. Nice long arms for installing the grill via the base hole.

 

Second Type. LHD and correct. Toe adjustment centre rod. Side rods fixed length. Varamatic is the exact opposite.

 

Once I got my head out of my a I figured it out! Everything buttoned up with some minor adjusting to do. The steering wheel and road wheels actually look like they are pretty close. Sorry for all the bother. On to the next job.