SPL solid subframe bushings in S13?

[SupaDoopa]

Well, everywhere I search, I get kind of shaky results. I'm assuming this part needs to be cut out and this is where the bushings install, but before I hack up a good subframe, I figured I'd ask.

Yes, I searched.

So, I cleaned out what SEEMS to be the cage but clarification without flaming would be helpful. Is this what needs to be cut out to continue the process to install the bushings or do the solids drop in and install from there? Any help would be greatly appreciated.

Picture:


Notice the lip? Now, does that 'sleeve' need to be cut out? All the other write-ups seem to be for energy suspension kits and not the solids. If anyone can find either an in depth write-up to help aid me or let me know, that would be great. I am going to make a write-up when done to clarify the confusion.