NOTE : Keep in mind the head bolts are torque to yield type and cannot be reused !

Using a socket wrench and lightly turn the bolts until they stop. Now for the very precise part.
You need to get your torque wrench out now and fit it with a 3" extension and a 15 mm socket.

Using the sequence illustrated, torque all 10 15 mm bolts to 22lb-ft.

Now take a felt tip marker and draw a horizontal line on the head of each bolt. This is very important.

Next, using the sequence illustrated, turn all 10 15 mm bolts an additional 90 degrees using a large socket wrench and a lot of muscle.
Try to get as close to 90 degrees as possible, you may have to do multiple turns of 30 degrees or 2 turns of 45 degrees.
When done, all the lines on the bolt heads should be totally vertical.

Next, again using the sequence, turn bolts 1 through 8 another 90 degrees.
This will take an immense amount of effort...if you have a buddy helping, both of you should turn the wrench simultaneously.
These 8 bolts will now all have horizontal lines on them

Using the sequence, turn bolts 9 and 10 an additional 50 degrees.
Again, this will take a lot of effort. 50 degrees should result in a diagonal line on the bolts

Finally, using the sequence above, torque bolts 11 through 15 to 22 lb-ft.