Step 1: Cut off several 3/16 x 2.5 inch bolts
Step 2: Debur the weld slag from the bolt holes
Grind the weld down just enough to allow the full hole to be exposed.
Step 3: Remove the old headers
It helps to squirt some PB-Blaster a few hours before you start. Breaking a bolt off in the head is a bad thing, which will result in a lot of cussing and several hours of crying..
My particular truck is missing just about all the smog stuff, and air-conditioning, making this step simple. Don't forget that sometimes things are easier to get to from the bottom. Don't be afraid to crawl under the vehicle.
Take the plugs out first too. The porcelian will crack pretty easy when you go to get the headers out.
Step 4: Clean up the block
Step 5: Install Studs
After threading the studs in (finger tight), align the gasket and slip the header in place. In this case, I was able to get the old header out through the top, but the new ones had to come in from bottom..
Step 6: Replace Studs for bolts
I used hex headed (standard) header bolts. The old headers had allen headed bolts. It's my choice to use the hex head. WIth this install the headers got in the way of the bolt heads, making an allen wrench difficult.
(I lost one bolt, so I had to reuse one of the old allen headed ones..)