Being a vet, it is much easier for me to fit within the regulations!
However, as at a younger age, they require less pinning down, anaesthetic etc, I have done my last 3 litters myself at home, between 3-7 days old.
I have had 3 of them develop hernias however, as the way pig testicles descend leaves things with a chance of leaking from inside the abdomen at the groin area. One survived, with surgery to replace the intestines (again as a vet, I could get him into surgery and fix him up very quickly!), but two unfortunately died (one while under anaesthetic to replace the intestines).
Just keep a really close eye on them post castration, if they are off colour, or any swelling in the groin area, or anything poking out from the castrate wounds, take them straight in to the vet surgery.
With older pigs, the vet may do things slightly differently, so reducing the risk of hernia further, but I cannot tell you exactly what technique someone else would be using.
When I did it, my OH fed the sows in one corner, I took a board in to block the door, picked the young piglets up out of the house, placed them in one of these fantastic new floppy buckets, the kind you can scoop both handles together. As your piglets are likely to be much bigger, and out and about, it is likely to be worth having some food to distract the sow, and someone to help fend her off, if your arms are full of piglet!, but picking them up and holding them in your arms (right way up, they get annoyed being upside down!) is probably the easiest way.
Then you can stick them, one by one, into the area you have to put them
Good luck!