Stock suspension help/insight

[Spackle100]

Hey Guys, this is my first build so...
I am putting on some new stock bits for my front suspension (58 1/2 ton) and I got a few questions...

This is the front outer threaded sleeve for the shackle. I received a new one (and threaded bolt) with the shackle kit I ordered from LMC. Would it be stupid to leave the old threaded sleeve in there? If I shouldn't, how do I get this out?
Outer:


Inner:


Second question is for the rear leafsrping. Should I remove these sleeves (in the bracket) too? And where can I get a replacements?


Thanks!