I need to add $58 to my federal gross. For the 401k

If you made contributions to your 401K, this will show on your W-2 in Box 12.  When you enter your W-2 in TurboTax, this amount will be picked up to see if you qualify for a Saver's Credit.  TurboTax will let you know if you do, or you can review this in the Deductions & Credits section. 

To go back to your W-2 to check your entries, type 'w2' in the Search area, then click on 'Jump to w2'.

You can EDIT your W-2 from the W-2 Summary page.

If you took a distribution from your 401K, you will receive a 1099-R to report this.  You may not get this document until early February. 

Click this link for instructions on How to Enter a 1099-R.

What is the $58 from?  401K contribution or distribution?  Or please add more details to your question.  Why do you need to add it to the gross?