I filled one rubber with grease and put it in place, then I put some grease on the caliper guide pins and pushed that all the way through from the side without rubber, filled the other rubber with grease and put the ring back in, put that rubber in place and positioned the caliper guide pins, making sure the rubber collar is in the groove in the caliper guide pins. With all that grease inside there's no more room for water or dirt and that way it will stay clean and lubricated.
Put the caliper back on. Put the new O-rings on both sides of the banjo bolt of the brake line, don't tighten it yet, just screw it in by hand. Be sure to put the brake line/bolt in the slot on the caliper so it's in the right direction.
Next you take the new brake pads and put a little bit of copper grease where the pad touches the piston ( on the inside pad ) and some copper grease on the outside pad where it touches the to "fingers" of the caliper.
Also put some copper grease on the inside of the 4 clips where the pads sit. Don't get any on the brake disc.
The last time you take the copper grease brush is to put some on the threads of the small caliper bolts. Tighten them to the specs in the manual too. Now tighten the banjo bolt to the specs in the manual.
Looks like new, brakes like new ! Now all that's left to do is bleed the brakelines and you're ready to go !!
Do a short test drive, checking that everything works perfectly and nothing leaks before you take it out for a spin !