haha yeah i just bought the first one of these that i've bought since they quit making them black... bummer, that black paint was awesome.
yeah they totally changed the silencer design, mine had the same issue. too bad because the old silencer was great, really well made and it secured with a snap ring.
you gotta put the studs through the two holes, then shove that aluminum outer tube until it goes over the cap, then shove it it on. get the nuts on there (i'd use some loctite) and torque them down. you can probably over tighten them to where the aluminum tube actually jams over the end of the caps, so stop before that happens but get them good and tight.
Depending on how it works, i might go back in and put a bead of silicone sealant where that goes together and really seal it up.
shame they changed things, i see treats reviews saying the silencers break... which was never a problem with the old ones, they were super well made and never gave me any trouble.
either way, its a great pipe and you'll be happy with the performance, the sound might be even better now that the silencer is bigger