How to write off LLC investment in startup

I've been a passive member of an LLC investment since 2010, and for years the company hasn't had any material change in their business.  My annual K-1 always has 0 in box 1, and TurboTax has carried forward a passive loss of -$5002 (box 1 - ordinary income) and -$857 (non-portfolio long-term capital loss).  

 

I would like to write this investment of $5000 off, since I believe it is worthless.  But I need to know exactly how to do this in Turbotax. 

 

Thank you in advance for your assistance!