Selling positions generally will not meet margin calls because funds from the sale are not actually available till settlement. Further, selling rather than depositing cash also has a downside (read the margin agreement). And, the Day Trading call, once generated, must be met regardless of whether the positions are still open.
Wisdom suggests that if you do not have $25,000, do not intentionally day trade. Further, if you do not have the cash to cover what you buy on margin, don't.