That is the correct procedure and it needs to be done carefully. You don't want any interruptions in one of the sequences such that you lose your place. To be safe you can mark each bolt with a daub of paint. Then if you do get interrupted you can see which bolts you've already done.

Also, you need to measure the length of each bolt if they are used bolts and see that they are no longer than specs. If so they are stretched too far and should not be used.

The REASON they do it this way instead of another torque reading is that the idea is to stretch the bolts such that they maintain clamping pressure. Once you get to the stretching point, the torque does not change much. You could not achieve this with a torque measurement.

Get in a comfortable position with a good stout breakover bar and get ready for a workout. You will feel like you are just breaking the bolts in half.

Good luck,