NHS Podiatrist here (just when you need one ) 
The actual procedure start to finish takes about an hour ,
Do you want the graphic detail?
OK
First , he'll have had the pre-assessment and it will have been explained . Then on the day , get him to have his breakfast or lunch , go to the loo before he goes in.
If he wants he can take headphones and music but he'll need to listen to all the prep first and give consent (and you will need to sign the consent forms)
He'll need an open toe sandle to wear on the way out .
His toe will be cleansed , he'll most likely lie flat ( you don;t faint lieing flat) then he'll have two* injections , either side of the base of the toe .
It will sting (I always tell the patient that is the injection working) I have had Local Analgesia in my 2nd Year training so I know what they're like . Now they don;t allow Pod students to receive LA in practice .
When its numb( * they might need a top up injection if one of the nerve branches doesn't get infused ) it;ll feel heavy and numb. He'll feel pressure and cold but not pain. They should test it (poke with a sharp instrument)
He might want to sit up and watch .
Toe is wrapped in sterile drape and Iodine swab. Then the tourniquet (silicone ring) is applied . Nail is removed with a very fine elevator .
Check it all clear .
Phenol applied (timed)
Neutralised
Tourniquet removed and time noted (how long its been on)
It might bleed a bit once the tourniquet comes off . Its dressed .
His toe will be numb for a couple of hours . It is unlikely he'll need painkillers but if he does , no asprin.
They'll give you aftercare leaflets and an emergency number
He'll need to elevate his foot and keep it dry . Our dept redresses after 2 days then the patient will redress themselves . The first dressing is bulky and might have dry blood , usually comes off ok, but they will use sterile saline to soak it.
He should be fine after a couple of days all going well, he'll need roomy shoes and make sure no clumsy git stands on his toe .
Good Luck, its really not as bad as you think its going to be . The Pods who do our Nail Surgery do a lot of them .