Separated the two F-810E Spacers from the F-885 spacer, smoothed and deburred the edges of the spacers Leveled the fuselage side to side and front to back Marked a centerline to use as reference on the aft deck Clamped the horizontal stabilizer rear spar to the F-811B-1 stabilizer attach bars. Put in F-810E spacer under both sides of the HS-814-1 splice angle and used a 3/16 dill bit as a spacer under the center point of the horizontal stabilizer rear spar Centered the horizontal stabilizer laterally on the fuselage using the joint line where the right and left HS-603PP rear spar channels meet. Clamped the horizontal stabilizer rear spar tightly to the stabilizer attach bars. Clamped the HS-814-1 splice angle at both F-810E spacers Placed some spacers on top of each half of the horizontal stabilizer at the intersection of the HS-608 rib and the HS-603 rear spar channel and verified level. Needed to add one (1) .020 spacer under the right F-810E spacer