I recently replaced my crazed, faded lenses with aftermarket. The lenses are cheap but it is a very big job replacing them. The how-to videos don’t reveal just how difficult it is to remove the old lenses! It it’s doable. Just know it’s a full day per side.
Replacing the OEM halos is a great upgrade.
Also be aware BMW uses poor quality wire inside the headlight housing, it will crumble if you’re not gentle with it.
Would I do it again? NO. Would I pay somebody good $ to do it? Absolutely!