Short answer: before incorporation, you cannot "remove" a cofounder the way a board removes an officer, because there is nothing to remove them from. No shares exist to claw back, no board exists to vote. What exists is a web of promises, contributions and expectations between individuals.
That web is what has to be dissolved, and here is the sentence this whole note hangs on: you cannot fire a pre-incorporation cofounder, you can only dissolve a promise, and promises dissolve best in writing. Done cleanly, this is the cheapest cofounder exit that will ever be available to you. Done carelessly, it is the lawsuit that surfaces two years later, in the middle of your Series A diligence, wearing your old cofounder's name.
What you can and cannot do
You can decide who you continue building with. Before a company exists, nobody holds a legal position in it, and freedom of association is real: the remaining founders can carry the project forward with a different lineup.
You cannot erase what the departing person contributed, promised or was promised. Their code, their designs, their savings put into the server bill, the "you're getting twenty percent" said in front of witnesses in March: none of that evaporates because the team moved on. Unsettled, each item is a claim in waiting, and claims in waiting mature at the worst moments, because that is when they are worth the most.
The entire craft of a pre-incorporation removal is therefore not exclusion. It is settlement.
The clean sequence
First, inventory what exists. What did they actually contribute: code, cash, designs, customers, the idea and its assets? What was promised to them, in writing, in messages, out loud? What do they control today: repos, domain, accounts? Be honest in this inventory; its gaps are your future litigation exhibits.
Second, have the conversation, then settle on paper. The human conversation comes first, as in any breakup. Then a short written separation agreement does the real work: their contributions acknowledged and, where real, compensated or converted into a modest, defined stake in the future company; all IP assigned in writing to the continuing project or its future entity; accounts and access handed over; promises mutually released; and the story agreed. Fair recognition is not generosity, it is the purchase price of finality. The departing cofounder who feels dealt with honestly signs and moves on. The one who feels erased calls someone like my former self.
Third, only then, incorporate. Founders regularly ask, quietly, whether they can just incorporate "around" the person: form the company with the remaining team and let the awkward history stay outside. Mechanically, yes. Legally and practically, the history does not stay outside: unassigned IP, evidenced promises and contributed money follow the project into the new entity, and every diligence process is designed to find them. Incorporating around an unsettled cofounder does not remove the problem; it seals the problem inside the foundation.
If you had a founder agreement
Everything above still happens, but with a script: the agreement's vesting says what was earned, its leaver provisions class the exit, its IP clause already assigned the work, its buyback mechanics price what returns. The difference is not that the separation becomes painless; it is that it becomes administration instead of negotiation. If you are reading this note before any conflict exists, that is the entire pitch for signing one this week.