Kind of dirty but this is
where you start. Carefully lift out the torque converter - being careful
to NOT remove the splined shaft that goes into the A/T to drive the
hydraulic pump. Then carefully wrap the opening and shafts so that no dirt
gets in.
The next part of the game is to achieve two things-
a) Make a hole in the bell housing casting so you can put a nut
on the KEP stud that will eventually pass through the hole described
below.
b) Drill out the existing threads and make a hole all the way
through.
In the end it should look something like this:

Making this hole requires slow patient action - my technique is to
first scribe the centre line of the eventual stud hole on the web of the
bell housing casting - then at 90 degrees to that line scribe a line about
3/8ths of an inch from the circular ring where the nut is going to
rest. On this line centre punch two spots 5/16ths on either side of
the stud hole centre line. Then starting with a small drill make two holes
where you centre punched. Then use larger drills to open these two holes
up to 9/16ths or 5/8ths inch. This kind of defines the outer edges of the
hole and now the fun begins. Using either a hand file or a Dremel tool cut
out the web between the holes and make the hole nice and flush with the
ring in the casting. Two things to remember:
1) Make the hole just big enough to get a ring type wrench on the 17 mm
nut.
2) keep all corners of the hole round with no sharp notches (this helps
prevent stress risers that could lead to cracking of the bell housing)
Here is a picture of the wrench on the nut:

Once you have the hole in the casting - you can drill the threads out
and make the hole go right through the ring in the casting. This wants to
be a clearance hole the same as the bottom two stud
holes.