Getting paid
Team members can sell equity back to a company.
Companies can buy equity back regularly (similar to salary) or as a one-off payment (similar to dividend or exit payout).
Companies set the offer price and contributors decide whether to sell. The price they are offered fluctuates and will be determined by supply and demand. If there are more sellers prices get driven down, if there are more buyers prices get driven up.

Buyout Clauses

Once the price reaches a certain level, a contributor may be forced to sell.
If a buyout clause is set then the company can force the team member to sell for the buyout clause limit. If the buyout limit is not set then a contributor must accept the transaction for it to be valid.

Completing the Sale

This is not currently available on platform, for a workaround see below.
For a contributor to sell equity back to a company, the CEO arrange the value transfer off platform and then transfer equity back to the company in the 'Transfer Equity' section of the CEO menu.