Is there a guide anywhere from people who have replaced the inlet manifold throttle body vacuum setup with an electric vacuum pump somehow linked to the brake pedal switch?

I've read quite a few people have done it, but can't find if anyone has done a walkthrough guide with tips and tricks.

Can't give you a walk through guide but the best thing I did to my series three.
Remove the manifold butterfly/linkage and blank off with 1/4" (6mm) bolt/studding and sealing washers.
Source an electric vacuum pump. I used a Hella U28 ( a Volvo part)
Mount on the bulkhead close to the servo and connect with a short vacuum hose.
Electrics are triggered from the brake light switch via a relay.
Flog the vacuum tank they are saleable.
There used to be a Dutch e-Bay seller listing the Pump and providing a wiring diagram.
Downside of the conversion is the noise from the pump if you sit in traffic with foot on the brake.
Good Luck. I sold my series three a few years ago now but still remember the improvement.
Conversion took around 2 to 3 hours and £70, will cost a bit more now ?