Is it possible to remove planets from KSP?

[KlunkWorks]

I'm aware that there are mods that allow for different/additional planets in KSP. I'm interested in REMOVING planets. I use different  builds of KSP for different types of craft, and i got to thinking, in my aircraft build, i never use the other planets. 

1. Is there a way to remove planets/asteroids/etc, basically everything BUT Kerbin and Sol? deleting stuff/and or mods basically any way of accomplishing this short of getting into unity, or writing some type of patch.
2. If I were able to do so, would there be any noticeable or even measurable gain in performance due  to running  a less populated environment? (not sure if that's even how that works lol)  i have a big kid PC, but also frequently run ksp on a MacBook, so every little bit helps. 

[Gotmachine]

1. Kopernicus
2. Very marginal gains, unlikely to make any visible/significant difference in practice.

[jimmymcgoochie]

Most planet packs have to remove all the stock planets before adding their own so you can probably find the required Kopernicus config in a planet pack somewhere. I doubt it’ll make much of a difference to performance though.

[KlunkWorks]

Thanks! yea i'm not expecting much. I'm probably a little on the obsessive side with some things. I use a build of KSP where i've removed everything that i can from the files - parts, sounds, fx etc and the game still load lol. No Squad parts, nothing, just whatever is currently being tested. It loads up on a 2015 MacBook pro in under 15 seconds lol.  It's been a curiosity over the years as to how much can one actually remove and still have a playable game lol.