I'm an outside contractor sales rep. I have a W-2 from the employer related to my expenses. Accidentally put them in self employed expenses. Should I change it?

It depends.  Does your W-2 have the box checked as a statuatory employee?

no, it does not.

Yes, you will need to change them.  A W-2 reports employee income and is treated differently than your self-employment income.  A W-2 (not a 1099-MISC) would have expenses reported against it on Form 2106 instead of the self-employment section.

It seems a bit strange you would receive a W-2 instead of a 1099 for contract work, but it's not impossible.  (If you received both from the same employer, then you would either split the expenses against both, or you might be able to justify just counting them against the self-employment if the nature of the W-2 has few or no expenses against it, like a taxable reimbursement for expenses you paid for).

If, on the other hand, you only received a W-2, and have no self-employment income besides what is reported on the W-2, then you would not claim expenses for self-employment income.  You would report the expenses on Form 2106.  Here are two FAQs to help you to understand how to do this:  

What expenses may be claimed:   https://ttlc.intuit.com/replies/3300622

Where to report in TurboTax:  https://ttlc.intuit.com/replies/4800418