Leave a company
In your personal space, open Settings → Companies and press Leave beside the company under Companies you have joined. Or switch to the company's space, open Settings → Company and press Leave company. Either way you are asked first: type leave and press Leave company. The desk goes back to your personal space. The time you tracked there stays with the company. The owner cannot leave their own company.
Remove someone
In Settings → Company, press Remove beside the person. The owner can remove anyone; admins can remove members.
What happens to their work
Everything they tracked and wrote in the company's space stays with the company, so nothing it relies on disappears with them. Their personal space is not touched.
Personal and Company plans
What is free, what the Company plan adds, and what it costs.
Start a company
Take the Company plan, name your company, and the desk opens on its new space.