I spent a lot of time yesterday trying to get the brand new caliper dust boot to seat as part of my goal to rebuild my brakes and bearings. 
The kit I bought is via Amazon. 

Centric Parts 143.42008 Caliper Kit
I had lubed the caliper cylinders with brake fluid, installed the o-ring and forced (and I mean forced) the piston in partially before trying to seat the dust boot. I ended up tearing the new boot as it was pretty impossible to get the seal wedged back into the cylinder and seated.
My question is whether anyone has guidance to make this task easier? I’ve ordered a replacement kit and hope that the centric kit was badly sized. 
Any help would be appreciated. 
Best
Brent

Sent from my iPhone