DIY or shop ?

I'm curious on the N62 stem seal repair. There was the recent blurb about the local master tech doing it as a side job for $2500 and knocked it out in less than a day.

I was just at my Indy this weekend for him to scan the car for a airbag light and we were chatting for a bit. I did not go into much details but he mentioned the stem seal failures on N62 and that dealer rate of $8K and I asked him how much were they doing the job for, and I was told , a smigen less but not too shy from the $8.

Just wondering what parts / procedure is one on the 8K versus the weekend warrior 2,500 ....