itch.io

There are 2 ways for now. (Potentially a 3rd way could come later, if it gets re-used from Lust Doll Classic.)
The first way is to go to the New Ark science tower and talk to the receptionist. Doing so will start a quest line for one of the "important" characters.
The second way is a kinky scene involving Mistyra, back at the abandoned base that put them on you in the first place. I'll try to put the method beneath the "View rest ↓" in case you want to find it yourself.

First you'll need to raise your Res stat to close to 20, or higher, so it can be at least a 13 after a 20% penalty.
Next you need to encounter Mistyra. Defeat her in combat with any method you choose, and when she goes to retreat, pursue her, and she will promptly punish you for daring to chase her while covered in parasites she can control.
She'll demand you lick her, and you need to keep resisting.
Enjoy the show. heheh

Pretty sure you can get it removed in the new ark labs - on the floor with blue tiles and if memory serves north / up from the police station.

I remember one of the NPC's mentioning something about it and read something on the wiki about it so try there.

Whoa, a Actual no extra Human Character...

go to the new ark lab, there is a becth or a medical bed, there will be a option to remove parasite