How hard would you say it is for someone who’s never done it before?

2nd gear in the 4L60E in my c10 gave up the other day. Pretty sure that the whole trans needs a rebuild since oil level and all is spot on and it was serviced late last year.

Seems like summit sells a master kit for around 200$ which would also upgrade it to handle 500 horses. On the other hand I could turn it for a stock replacement unit at a local trans shop for around 1400$...

See why rebuilding it myself seems really appealing?