If you can not get a W-2 from your employer, you can file Form 4852 Substitute for Form W-2, Wage and Statement.
Step 1. Download and print Form 4852 from the IRS.GOV website
Step 2. You will need to manually complete Form 4852
Step 3. You will enter this information on W-2 Income Page located on the left hand side under "Forms in Return" you will click on "Federal"
Step 4. Select "Income"
Step 5. Scroll down towards the bottom where it says "W-2 Income Page"
Step 6. Click on "Add New" and fill out the W-2 Income Page with the information on your Form 4852