coat the new o-rings with some silicone/or dielectric grease, and install them. next coat the two pistons with some clean dot-4 brake fluid, and carefully push them in through the o-rings.
I coat stuff only with the same brake fluid I'm using... I remember a few years back, everyone was saying
how the manual (pg 15-18) sez to coat the seals with silicone grease, but that some brake fluids
didn't get along with silicone grease very well...
-Mike
Makes sense considering our brake systems are incompatible with silicone based brake fluid.
Marty