I need to file a 1040x form for a w2 that was sent to me after i filed my taxes and received my refund. can you guide me thru the steps please?

Since you have received your refund, you are ready to amend. Be sure to include any refund or money paid on your amended return. You will be able to efile the amended federal form and maybe your state.  If you can't efile your state, you will need to print, sign and date, then mail your forms with tracking, no signature required.

Use these to help through the process:

• How do I amend my federal tax return for this year?
• I need to amend my state return
• Can I e-file my amended state return?
• Where’s My Amended Return? Track federal. 
• Make any payments to federal and state online. For federal,  IRS Direct Pay

There is a major omission in all the Amend directions.  It does not prompt you to save a backup copy of your files before amending.  Before amending save a pdf and tax copy.  Once you amend those are overwritten and you cannot get to the original copies.