From Breadwinner Manual

Action adjustment

The action is adjusted only after  the tension rod adjustments are made.  The action is determined by measuring the distance between the top of the 12th fret and the bottom of the string.  The Ovation Standard action pre-set at the factory is 5/64 for the bass E and 4/64 for Treble E.  To adjust the action, use the two recessed screws on either side of the tailpiece.  Note. If the action is not in the adjustment range, remove the battery door, raise or lower adjustment nut at the rear edge of the tailpiece.  Normal adjustment may now be made.

Intonation Adjustment

The intonation is adjusted by the screws (3) under the rear of the tailpiece as follows.  Play a harmonic above the 12th fret.  Listen to the tone for a few seconds and then carefully press the string down on the 12th fret.  If the pitch is flat, turn the screw counter-clockwise until the tone matches.  There will always be a slight tone difference between the harmonic and the fretted note, so it is important so it is important to let the harmonic ring for a few seconds before comparing its pitch to the fretted note.

From Preacher Deluxe Manual

Action Adjustment

Action is measured as the distance between the top of the 12 th  fret and the bottom of the string being measured. By adjusting the two recessed screws at either side of the tail-piece, the Preacher Deluxe can be set for any desired action. If the adjustment screws are tuned clockwise one turn, the action will be lowered 1/64". Counterclockwise rotation of the screw raises the tailpiece.

Your action setting will in part be determined by the string set you use. Standard action for Ovation 2E strings is 5/64' bass E string, 4/64" treble E string.

A tension rod adjustment will change the action. Therefore, do not set the action until the tension rod adjustment is correct. (see paragraph XIV)

There is a screw recessed in the back surface of the Preacher Deluxe body. This screw adjusts the angle of the tailpiece. Usually, most action settings can be made without adjustment of this screw. If an adjustment is desired, counterclockwise movement of the screw will raise the rear edge of the tail-piece. Clockwise movement of the screw lowers the rear edge of the tailpiece. Adjustment of this screw can alter in­tonation settings.

String Replacement

The frequency of, string replacement will depend on your playing habits. Generally, strings should be replaced about every month to insure good tone and intonation. We recommend that you replace the strings on your Preacher Deluxe with Ovation strings.

At the tailpiece

Before removing the old strings, look closely to see how they have been threaded through the tailpiece. Make a slight bend in the end of the string to facilitate thread­ing. Then, carefully thread the string through the tail-piece and over the saddle.

At the peghead

After the string has been threaded through the tailpiece, make a 90° angle bend 1-1/2" past the appropriate tuning peg post at the peghead.

Insert the string into the hole in the post so that the bend fits snugly into the post

and the free end of the string points away from the center of the peghead.

With one hand, hold the string tightly in its slot in the nut. With the other hand, turn the tuning key until there is tension on the string. By convention, strings should always wrap onto the tuning peg posts from the center of the peghead.

For ease of restringing, it is recommended that you replace the outside strings first and work toward the middle strings. After all the strings have been replaced, trim the string ends 1/8" from the tuning peg posts.

Extract from Preacher and Viper Manual