S Corp paying social security & medicare late

S Corp working on 2019 taxes. I am the only employee. During the year I simply took disbursements. I need to correct now to make some of that wages and also take out social security and medicare withholding. I've figured out what to do, but do not know which form to use to do it. Forms are 940, 941, and 944. I need a bit of guidance re how to proceed. Same re W-2s and W-3s. Thanks.