PaladinNO: What DLC specifically are we talking about? Content like the Silverhand's optional clothing outfit?
I don't know how to uninstall it, but there is a toggle in the menu to disable it - and it is disabled by default.

The additional weapons can just be put in the storage, either in your apartment or from any (owned) vehicle with a trunk / boot, if you don't want to use them.

Most of what is referred to as "DLC" is just included with the patches anyway, though you get some extras if you connect your game with GoG Galaxy (which is just information collecting spyware anyway - literally 0 other reason to offer enticement if you do it).

PaladinNO: The new apartments are a part of the 1.5 patch.
https://www.cyberpunk.net/en/news/41435/patch-1-5-next-generation-update-list-of-changes

Those are non-removable, sorry. Buying them will unfortunately also eventually come up as a mission.
They call them a DLC, but frankly, that's just content that should have been there with the initial release.

You don't have to use them though. And you can just buy them from your default apartment PC (to make the mission go away) and never visit them, there is nothing in the game that forces you to use them in any way.
Their lack of use is a shame though, I wouldn't mind taking Panam or Judy over to my place for some sheet action.