Torque spec is 22 lb-ft for the bridge pin bolt (center bolt). Factory manual does not call for any, but you can use a small amount of blue (low strength) thread locker if you want. High strength will likely snap the bolt off inside the pin the next time you try to remove it since it's a pretty small bolt.
As Stephen previously mentioned, no grease or anti-seize is needed. Just take the old pads out and put the new ones in.
For factory manual process, the how-to guides on the forums do a pretty good job of covering it. Nonetheless, basic steps are:
- Drive pad retainer pins out.
- Remove pad spring.
- Remove bridge pin.
- Pull old pads out.
- Use spreader or other wide/flat tool to move all pistons back at once. Keep an eye on the brake fluid reservoir to make sure you don't overflow during this step.
- Slide new pads in.
- Put bridge pin back in and torque to 30 Nm (22 lb-ft).
- Put spring back in.
- Drive pad retainer pins in.
- With engine off, slowly push brake pedal to about 2/3 of full travel and slowly release.
- Repeat previous step until brake pedal becomes firm.
- Top off brake fluid if needed.